(4x-3)² -9(x+5)(x-2) = 7(x+2)²- 8

Răspuns :

16x²-24x+9-9(x²-2x+5x-10)=7(x²+2x+4)-8
16x²-24x+9-9(x²+3x-10)=7x²+14x+28-8
16x²-24x+9-9x²-27x+90=7x²+14x+20
16x²-9x²-7x²-24x-27x-14x=20-90-9
0x²-65x=-79
65x=79
x=79/65
(4x-3)²= 16x² -24x+9
(x+5)(x-2)=x² -2x+5x-10= x² +3x-10
(x+2)²=x² +4x+4

16x² -24x+9 -9(x²+3x-10)=7(x² +4x+4)-8

16x² -24x +9 -9x² -27x +90 =7x² +28x +28 -8

7x² -51x +99= 7x² +28x +20

-51x +99=28x +20

-51x-28x=20-99

-79x = -79

x= -79/-79

x=1