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When a=1, the inequality is different from the 2x<4 solution set, so a is not equal to 1, i.e. (a-1) is not equal to 0

a-1) <0, both sides of the inequality are divided by (a-1) at the same time, which becomes x>(a+5) (a-1) is different from the solution set of the latter inequality, so (a-1) > 0

So both sides divide by (a-1) at the same time and the inequality becomes x<(a+5) (a-1), and the solution set of the latter inequality is x<2, and the two solution sets are the same, so (a+5) (a-1)=2 i.e. a+5=2a-2 so a=7

n^2-(50n-625)

n-25)^2

Because (n-25) 2 0

Therefore, when n=25, the two classes are the same, and when n>25, there are more classes A, and the number of more is (n-25) 2

Substituting y=3x: 14x-3y=20 obtains: 14x-9x=20, x=4; y=12.

Replace x=4; y=12.Substituting: 2x-y-4m=0, 8-12-4m=0, m = 1

Get: xy (x+y)=48 16=3

Solution: Substituting y=3x into: 14x-3y=20 obtains: 14x-9x=20, x=4; y=12.

Replace x=4; y=12.Substituting: 2x-y-4m=0, 8-12-4m=0, m = 1

Answer: x=4; y= =-1. xy/(x+y)=16/16=1.

2x squared + ax-y+6) - (2bx squared - 3x+5y-1) (2-2b) x + (a + 3) x - 6y+7

It has nothing to do with the value of x.

2-2b=0

a+3=0a=-3

b = 1 Then, substitute the value of ab into the polynomial.

3 (square of a - 2ab-b squared) - (4a squared + ab + b squared).

The condition description x squared, the coefficient in front of x is 0, so a = -3, b = 1, and the latter can be brought in.

The internal cause of the water cycle is the easy conversion of water in gaseous, liquid and solid states under normal environmental conditions, and the external causes of the water cycle are solar radiation and gravity, which provide the energy for the physical state change and movement of water for the water cycle.