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The quadratic equations of one variable with two sum and two product of x ^ 2 + 3x-2 = 0 as roots are?
From the Veda theorem
The sum of two elements of X & sup2; + 3x-2 = 0 is - 3, and the product of two elements is - 2
-3+(-2)=-5
-3×(-2)=6
So the quadratic equation with roots of - 3, - 2 can be X & sup2; + 5x + 6 = 0
SOS ~ ~ ` urgent... Math problem... (about 1-ary quadratic equation ~ ~) thank you~
There are a few questions a... Kind people help
1. If x2-2 (M + 1) x + M2 + 5 is a complete square, then M=
2. If the equation (A2 + B2) x2-2b (A-C) x + (B2 + C2) = O has two equal real roots, B2=_____
3. If the equation 3mx2-nx-1 = O has the same root as the equation MX2 + 2nx-5 = 0, then M=_______ ,n=______
(Note: the following 2 represents the square... Meeting 1 is OK... It's better to have the writing process.. thank you.. ~ ')
m^2+5=(m+1)^2
m=2
delta=b^2(a-c)^2-(a^2+b^2)(b^2+c^2)=0
so b^4+2acb^2+a^2c^2=0
b^2=-ac
x=-2
so 12m+2n=1
4m-4n=5
so m=1/4
n=-1
You write me an equation with a quadratic coefficient of 1 and the sum of two real roots of 3?
x^2-3x+2=0
x^2-3x+2=0
(x-1)(x-2)=0
x1=1,x2=2
x^2-3x-4=0
x^2-3x-4=0
(x-4)(x+1)=0
x1=4,x2=-1
x^2-3x-10
Solution: x ^ 2-3x-10 = 0
(x-5)(x+2)=0
x1=5,x2=-2
The above equations satisfy two and three, and there are many more~
Use arithmetic to analyze the solution in detail, not equation
There are 100 big and small balls in this paper. The big 1 / 3 is 16 more than the small 1 / 10. How many small balls are there?
Because: the big 1 / 3 is 16 more than the small 1 / 10,
So: the big is small (3 / 10 + 48)
There are 100 in all, and the small one is 1
The small number of balls is: (100-48) / (1 + 3 / 10) = 40
Solving problems with equations and arithmetic
The ratio of the number of parts completed by Party A and Party B in the first ten days of this month is 5:3. If they make another 300 parts, the ratio of the number of parts completed by them is 4:3. How many parts should they complete in the first ten days of this month?
Let them complete x.y parts respectively in the first ten days. Then, X / y = 5 / 3 (x + 300) \ (y + 300) = 4 / 3, x = 500, y = 300
Ask a math problem (solve it arithmetically, not by equation)~~~~
It's 0.4 yuan for each exercise book and 0.28 yuan for each picture book. Xiaoxuan's father gave her 10 yuan, just enough to buy a certain number of exercise books and picture books. As a result, when Xiaoxuan took the money to buy them, he reversed the number of the two books, and the salesman gave him 0.96 yuan. So, how many exercise books and picture books did his father intend to buy for Xiaoxuan?
0.96 / (0.4-0.28) = 8, so the difference between the two books is 8, the solution is (10 + 0.28 * 8) / (0.4 = 0.28) = 18, the small picture book (10-18 * 0.4) / 0.28 = 10!
A and B each have a number of extra-curricular books. Given the number of books they have, B is 13 of A. if a lends 30 to B, B is 23 of A. how many books do they have?
Let a have X copies and B have 13X copies. 13X + 30 = (X-30) × 2313x + 30 = 23x-20 & nbsp; & nbsp; 13X = 50 & nbsp; & nbsp; X = 150 and B have 150 × 13 = 50 copies. A: A has 150 copies and B has 50 copies
Xiao Li calculates the sum of several continuous natural numbers starting from 1. He accidentally takes 1 as 10 and gets the wrong result, which is exactly 100. So what's the largest one of these numbers Xiao Li calculates?
Let the largest number in the sequence, that is, the last term, be X. the feasible equation is: (1 + x) x △ 2 = 100 - (10-1) (1 + x) x = 182 = 13 × 14 = 13 × (13 + 1), x = 13. A: among the numbers calculated by Xiao Li, the largest one is 13
What are the characteristics of solving problems by equation compared with solving problems by arithmetic
Do help me!
emergency
Come on
Equations are easy to think about and arithmetic easy to write
There are few steps in arithmetic, but sometimes reverse thinking is needed. If you are afraid of making mistakes or can't turn around, it's better to be practical in equation. If you pursue speed, arithmetic is better
Arithmetic is generally used in primary school, but it will not be used after middle school. But in fact, I think it can improve the ability of solving problems in primary school. It is too simple to use equation in common problems in primary school
Please use arithmetic or equation
The four brothers bought a TV for their father. The money from the eldest brother accounted for 1 / 2 of the other three; the money from the second brother accounted for 1 / 3 of the other three; the money from the third brother accounted for 1 / 4 of the other three; the money from the fourth brother accounted for 520 yuan. How much is the TV worth?
The number of the eldest in the total: 1 ÷ (1 + 2) = 1 / 3
The number of the second in the total: 1 ÷ (1 + 3) = 1 / 4
The proportion of the third in the total: 1 ÷ (1 + 4) = 1 / 5
1-1 / 3-1 / 4-1 / 5 = 13 / 60
The total amount is: 520 △ 13 / 60 = 2400 yuan
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