(a-8)(a+8)-5a(6-a)=a²-64-30a+5a²=6a²-30a-64=3a²-15a-32
(a-3)(a-2)-(a-4)²=a²-2a-3a+6-(a²-8a+16)=a²-2a-3a+6-a²+8a-16=3a-10
(b+2)(b-2)+(5b+4)²=b²-4+25b²+40b+16=26b²+40b+12=13b²+20b+6
5(a+2)²-(5a²+29a)=5a²+20a+20-5a²-29a=-9a+20
(5x-4)²-3x(5-x)=25x²-40x+16-15x+3x²=28x²-55x+16
(p+8)(p-3)+(p+7)²=p²-3p+8p-24+p²+14p+49=2p²+19p-24
(a-x)²+(a+x)²=a²-2ax+x²+a²+2ax+x²=2a²+2x²=2(a²+x²)
(2ab-b)²+2(a-b)²=4ab²-4ab²+b²+2(a²-2ab+b²)=b²+2a²-4ab+2b²