1) (х+2)²-(х-3)(х+3)=(х+2)²-(х²-9)=х²+4х+4-х²+9=4х+13
2) (7a-5b)(7a+5b)-(4a+7b)²=(7a)²-(5b)²-((4a)²+2*4a*7b+(7b)²)= 49a²-25b²-16a²-56ab-49b² =33a²-56ab-74b²
3) (x+5)²-(x-1)²=48
x²+10x+25-x²+2x-1=48
12x+24=48
12x=24
x=2
4) (2x-3)²+(3-4x)(x+5)=82
4x²-12x+9+3x+15-4x²-20x=82
-29x+24=82
-29x=58
x= -2