Question

1.若(1/2a-x)^2=1/4a^2+1/2y·a+1/9,则x,y的值分别为_____.

Answer 1

1.若(1/2a-x)^2=1/4a^2+1/2y·a+1/9,则x,y的值分别为_____.

[1/2a-x]^2=1/4a^2-ax+x^2

-x=1/2y

x^2=1/9

x=1/3,y=-2/3或者x=-1/3.y=2/3

2.-(2x-3)^2+(3x+2)^2=5x(x-3)+4

-4x^2+12x-9+9x^2+12x+4=5x^2-15x+4

39x=9

x=3/13

3.(6x+5)(6x-5)-(6x-1)^2=-20

36xx-25-36xx+12x-1=-20

12x=6

x=1/2

4.(x+4)^2-(x+4)(x-4)=8

xx+8x+16-xx+16=8

8x=-24

x=-3

5.2(2y+1)^2-8(y+1)(y-1)=34

8yy+8y+2-8yy+8=34

8y=24

y=3