2÷(x+1)+4÷(x²-1)=1

2÷(x+1)+4÷(x²-1)=1

A:
2/(x+1)+4/(x²-1)=1
Multiply both sides by X & # 178; - 1 to get:
2(x-1)+4=x²-1
x²-2x-1=2
x²-2x-3=0
(x-3)(x+1)=0
The solution is: x = 3 or x = - 1
The test shows that x = - 1 is the increasing root of the fractional equation
So: the solution of the fractional equation is x = 3

Decomposition factor: 4 (x + y) ² - 20 (x + y) + 25

This is a complete square formula
4(x+y)²－20(x+y)+25
=[2(x+y)]²-2x5x2(x+y)+5²
=[2(x+y)-5]²

1.X4-4X² +16 2.1/4X² -28XY+Y² 3.-a²+8ab-4b²

a²x²+16ax+64

a²x²+16ax+64
=(ax)²+2*8*ax+8²
=(ax+8)²