Let x = 1. Y = - 1 and x = 2. Y = 2 for the two groups of solutions of the quadratic equation AX + by + 2 = 0, and try to judge whether x = 3 and y = 5 are the solutions of the equation

Let x = 1. Y = - 1 and x = 2. Y = 2 for the two groups of solutions of the quadratic equation AX + by + 2 = 0, and try to judge whether x = 3 and y = 5 are the solutions of the equation

Replace x = 1. Y = - 1 and x = 2. Y = 2 into ax + by + 2 = 0
The solution is: a = - 1 / 2, B = - 3 / 2
That is: (- 1 / 2) x - (3 / 2) y + 2 = 0
X = 3, y = 5 are not 0, so they are not solutions

If {x = 1, y = 6 and {x = - 3, y = - 4 are the solutions of the equation AX + by-7 = 0, please judge whether {x = 3, y = 11 is the solution of the equation

Is its solution, a = - 5, B = 2

Solve the equation a square + 2a-1 = 7, write the result and write the process

a^2 + 2a - 1 = 7
a^2 + 2a - 1 - 7 = 0
A ^ 2 + 2A - 8 = 0 find two numbers, multiply by - 8, add to 2. Get 4 and - 2
（a + 4)( a - 2)= 0
So, a + 4 = 0, or a - 2 = 0
Answer: a = - 4, or a = 2

Solve equation 4-2a = root sign (square of a plus square of a)

4-2 pieces 2

How can the negative power of fraction be reduced to the negative power of (half)

The negative power of a fraction reverses the numerator and denominator of the fraction and changes the exponent to a positive number
（a/b)^(-n)=(b/a)^n

A 200 meter long train has passed the 340 meter long bridge for a total of 30 seconds. How many meters does this train travel per second? If this train travels 27 meters per second,
How many seconds does it take for the whole car to cross the bridge?

(200 + 340) △ 30 = 18 (M / s)
The train runs 18 meters per second
(200 + 340) △ 27 = 20 (seconds)
If the train runs 27 meters per second, it will take 20 seconds for the whole train to cross the bridge

Cut a round piece of paper and put it together into an approximate rectangle with a width equal to the radius and a constant area. The circumference of the rectangle is 33.12 cm
How many square centimeters is the area of a rectangle

Let the radius of the circle (that is, the width of the rectangle) be r and the length of the rectangle be X
If the area of a rectangle is the area of a circle, then: X · r = π · R & sup2;, x = π · R
Then: the circumference of rectangle = 2x + 2R = 2 π · R + 2R,
The results show that: r = perimeter of Rectangle / (2 + 2 π) = 33.12 / (2 + 2 π) ≈ 4
So: area of rectangle = area of circle = π · R & sup2; = 16 π ≈ 50.24 (CM & sup2;)

What's the number of 2 to the power of 2010? What's the specific operation process?

The number of the n-th power of 2 is in the order of 2, 4, 8, 6, 2, 4 in a cycle
Because 2010 △ 4 = 502 more than 2
So the number of 2 to the power of 2010 is the same as that of the other 2, which is 4

The charging standard of a taxi in a city is: the starting price is 12 yuan (within 3 kilometers, including 3000 meters), and then every kilometer (less than one kilometer is one kilometer)
It's an extra 3 yuan. Please calculate how much it costs to drive 8 kilometers

Within 3km (inclusive): starting price, 12 yuan
The cost after 3km: (8km-3km) * 3 yuan = 15 yuan
Therefore, the total cost of 8 km is: 12 + 15 = 27 yuan

In order to beautify the environment, a community is going to build on a rectangular land ABCD
In order to beautify the environment, a community is going to build a rectangular leisure square EFCG on a rectangular land ABCD. In order to keep the △ AKH of the city's cultural relic reserve from being damaged, the top e of the leisure square can not be in the cultural relic reserve. It is known that ab = 50m, ad = 40m, AK = 15m, ah = 10m
(1) When point E is the midpoint of HK, how many square meters is the leisure square?
(2) When point E is located on HK, what is the largest area of leisure square? What is the largest square meter?
Please write the procedure and the quadratic function expression

Let Ge extension line intersect AB at m, Fe extension line intersect DA at n, let am = x, an = y (1) when e is the midpoint of HK, m and N are the midpoint of AK and ah respectively, that is, x = 7.5, y = 5, then square area = ef * eg = (ab-x) * (ad-y) = 1487.5 (2) square area is represented by X and y, then s = (50-x) * (40-y) according to △ HNE and