A few more difficult questions

A few more difficult questions

The simple method is to put forward the common factor method, and then use the formula method (square difference formula, complete square formula) and then cross multiplication: ①: x ^ 2 (a-b) + (B-A) ②: x ^ 2y-2xy ^ 2 + y ^ 3 ③: (B-A) ^ 2 + 2 (a-b) + 1 ④: (x ^ 2-y ^ 2) ^ 2 - (x ^ 2 + y ^ 2) ^ 2 ⑤: XY ^ 3-6x ^ 2Y ^ 2 + XY ^ 3 ⑥: (3a-b) ^ 2 -
Help me solve some factoring problems
-2a(a+b)+b(a+b) (x+p)^2-(x+q)^2 (a+b)^2-12(a+b)+36 (2a-b)^2+8ab
(x+y)^2-4(x+y-1) 4+(a-1)(a-5)
-2a(a+b)+b(a+b) (a+b)(b-2a)(x+p)^2-(x+q)^2 =(x+p+x+q)(x+p-x-q)= (2x+p+q)(p-q)(a+b)^2-12(a+b)+36=((a+b)+6)²(2a-b)^2+8ab = 4a²-4ab +b²+ 8ab= (2a+b)²(x+y)^2-4(x+y-1)=(x+y-2)^24+(a-1)(...
-2a(a+b)+b(a+b) =(a+b)( b-2a)
(x+p)^2-(x+q)^2 =(2x+p+q)(p-q)
(a+b)^2-12(a+b)+36 =(a+b-6)^2
(2a-b)^2+8ab=(2a+b)^2
(x+y)^2-4(x+y-1) =(x+y-2)^2
4+(a-1)(a-5)=(a-3)^2
(b-2a)(a+b) (2x+p+q)(p-q) (a+b+6)² (2a+b)² (x+y-2)²
(a-3)²
{3x-5y=-2
{2x+7y=40
The one above is a brace
{3x-5y=-2
{2x+7y=40
6X-10Y=4 1
6X+21Y=120 2
Formula 2-1
31Y=116 Y=116/31
X = 642 / 93 in Formula 1
There is piping at the Bank of the river, and the river water continuously flows to a dry pond on the bank. Assuming that the amount of water gushed out every minute is the same, if two pumps are used to pump water, the water in the pond can be pumped out in 40 minutes; if four pumps are used to pump water, the water in the pond can be pumped out in 16 minutes; if the water in the pond is pumped out in 10 minutes, at least how many pumps are needed?
Suppose that a cubic meter of water has been gushed out from the pipeline before pumping, B cubic meter of water is gushed out from the pipeline every minute, and C cubic meter of water can be pumped out from each pump every minute, then according to the meaning of the question: a + 40B = 2 × 40Ca + 16b = 4 × 16C, the solution is: a = 1603cb = 23C, if the water is to be pumped out in 10 minutes, at least
Use 30% and 75% antiseptic solution, and prepare 18 kg antiseptic solution with 50% antiseptic solution. How much should be taken for each of the two solutions?
Let 30% medicated liquid XKG, then 75% medicated liquid (18-x) kg, from the Title Meaning: 30% x + 75% (18-x) = 18 × 50%, solution: x = 10, then 18-x = 18-10 = 8, answer: 30% medicated liquid 10K, 75% medicated liquid 8kg
The process and answer of 30 mathematical binary linear equations
It's very urgent
(1) 66x + 17Y = 3967 25X + y = 1200 answer: x = 48 y = 47 (2) 18x + 23y = 2303 74x-y = 1998 answer: x = 27 y = 79 (3) 44x + 90Y = 7796 44x + y = 3476 answer: x = 79 y = 48 (4) 76x-66y = 4082 30x-y = 2940 answer: x = 98 y = 51 (5) 67x + 54y = 8546 71x-y = 5
1. The road from a to B is an uphill and a downhill. If the uphill is 3km, the average road is 4km per hour, and the downhill is 5km per hour, then it takes 54min to go from a to B, 42min to go from B to a, and how much is the whole journey from a to B?
2. It is necessary to prepare 18kg antiseptic liquid with 50% antiseptic liquid with 30% and 75% antiseptic liquid. How many kg of each liquid need to be taken?
3. When the length of a rectangle is reduced by 15cm and the width is increased by 6cm, it becomes a square, and the areas of the two figures are equal. What are the length and width of the rectangle?
Good answer and problem-solving ideas,
It's a system of linear equations of two variables
The first question is wrong. It should be: 1. The road from a to B is an uphill and a level road. If the uphill is 3km, the level road is 4km per hour, and the downhill is 5km per hour, then it takes 54min from a to B and 42min from B to A. how much is the whole journey from a to B?
1. Let the ascending slope X and the descending slope y Kmx / 3 + Y / 5 = 54 / 60x / 5 + Y / 3 = 42 / 60 from land a to land B add up to 8 / 15 (x + y) = 1.6x + y = 3km2. Let 30% want XKG and 75% want XKG. From the equality of solute before and after, we can get x + y = 1830% x + 75% y = 18 * 50% x = 10, y = 830% want 10kg, and 75% want 8kg
A student rides a bicycle from the school to the county. He first goes down the mountain at the speed of 12 kilometers per hour, and then arrives at the county by the level road at the speed of 9 kilometers per hour, which takes 55 minutes. When he returns, he goes through the level road at the speed of 8 kilometers per hour, and then goes up the mountain at the speed of 4 kilometers per hour to return to the school, which takes another hour and 30 minutes. (1) if the length of the mountain road is x kilometers, the length of the level road is y thousand How to set up equations? (2) If it takes x hours to go down the mountain and Y hours to go up the mountain, what about the equations? (3) If it takes x hours to go on a level road and Y hours to return on a level road, how can we set up the equations?
（1）x12+y9＝5560x4+y8＝9060；（2）12x＝4y9(5560−x)＝8(9060−y)；（3）9x＝8y12(5560−x)＝4(9060−y)
If someone rides a bicycle from place a to place B, if the speed is one kilometer faster than usual per hour, he can arrive seven minutes earlier. If he is one kilometer slower per hour, he will arrive eight minutes later
There are: 2: Xiaoming and Xiaoliang do addition, Xiaoming will be one of the addends after writing a zero, the sum is 2340, Xiaoliang will be an addend after writing a zero, the sum is 63.
3: The two objects move on a circle with a circumference of 100 meters. If they move in the same direction, they meet every 20 seconds; if they move in the opposite direction, they meet every 4 seconds. Find the velocity of each object.
1、 Let the velocity and time be V km / min and t min respectively, VT = (V + 1) (T-7) VT = (V-1) (T + 8) VT on both sides is about to be dropped, two binary linear equations, good solution ~ 2. Let the original two numbers be x and Y, followed by a zero is ten times, a few zeros is 0.1 times, then the following equation 10x + y = 23400.1x + y = 63 Ken
1) If the distance is 1 and the normal speed is x km / h, then 1 / (x + 1) + 7 / 60 + 8 / 60 = 1 / (x-1)
The solution is x = 3 or x = - 3. Through the test, x = 3 and x = - 3 are the solutions of the original equation, but x = - 3 is not suitable for the problem, so this person usually takes 1 / (x + 1) + 7 / 60 = 1 / (3 + 1) + 7 / 60 = 22 / 60 hours, that is, 22 minutes to ride from place a to place B
2) Let two be a and B respectively. From the problem, we can get the equations {10A + B = 2340,1 / 10A + B = 63
The quadratic equation of two variables
Given that the solution of the system of equations 3x + 5Y = m + 2 2x + 3Y = m (this is the system of equations) is suitable for x + y = 8, find the value of M + 2
From: 3x + 5Y = m + 2
2x+3y=m
By subtracting the two formulas, we get that x + 2Y = 2 and X + y = 8 form the equations
The solution is: x = 14, y = - 6
The result is: M + 2 = 12
Because 3x + 5Y = m + 2,2x + 3Y = M
So the subtraction of the two formulas gives x + 2Y = 2
Because x + y = 8
So we connect a system of equations with x + 2Y = 2
We get x = 14, y = - 6
Take the above value into 3x + 5Y = m + 2
So m = 12
It's not necessarily right. I hope to adopt it
3x+5y=m+2......(1)
2x+3y=m........(2)
(1) (2) x + 2Y = 2... (3)
And ∵ x + y = 8.......... (4)
(3) (4) y = - 6, x = 14
∴m=10.
By substituting x + y = 8 into 3x + 5Y = m + 2x + 3Y = m, we get the following results:
24 + 2Y = m + 2-1, 16 + y = m-2, 2 × 2-1, M = 10, so m + 2 = 12