Question

解方程 ⑴3x^2+4x-7 ⑵5（2x-1)^2=80 ⑶ (x+17)^2=49

Answer 1

3x^2+4x-7=0

1 -1

3 7=7-3=4

(x-1)(3x+7)=0

x=1 x=-7/3

5（2x-1)^2=80

（2x-1)^2=16

2x-1=±4

x=5/2 x=-3/2

(x+17)^2=49

x+17=±7

x=-10 x=-24