3х(3х+7)-(3х+1)2 упростить выражение 2)(у-2)(у+3)-(у-1)2 3)(p+1)2-(p+2)2 4)3(2a-5b)2-12(a-b)2 5)(3х2+4)2+(3х2-4)2-2(5-3x2)(5+3х2)

1)3x(3x+7)-(3x+1)²=9x²+21x-9x²-6x-1=15x-12)(y-2)(y+3)-(y-1)²=y²+3y-2y-6-y²+2y-1=3y-73)(p+1)²-(p+2)²=p²+2p+1-p²-4p-4=-2p-34)3(2a-5b)²-12(a-b)²=12a²-60ab+75b²-12a²+24ab-12b²=-36ab+63b²5)(3x²+4)²+(3x²-4)²-2(5-3x²)(5+3x²)=9x^4+24x²+16+9x^4-24x²+16-50+18x²==18x^4+18x²-18