Question

求北师大数学九年级上总复习的数学题(第9题的(5)(6)(7)(8)),请快速,

Answer 1

5.3x(x-1)=2-2x

3x^2-x-2=0

(3x+2)(x-1)=0 x1=-2/3 x2=1

6.)(x-1)(x+2)=70 ;

x^+x-72=0 (x+9)(x-8)=0 x1=-9 x2=8

7.x(x+6)=7 x^2+6x-7=0 (x+7)(x-1)=0 x1=-7 x2=1

8.(3-x)的平方+x的平方=9

(3-x)^2+(x+3)(x-3)=0

(x-3)(x-3+x+3)=0 x1=3 x2=0