1) 3x(3x+7)-(3x+1)²= 9x²+21x-9x²-6x-1= 15x-1
2) (y-2)(y+3)-(y-1)²= y²+3y-2y-6-y²+2y-1= 3y-7
3) (p+1)²-(p+2)²= p²+2p+1-p²-4p-4= -2p-3
4) 4(a+5)²-(4a²+40a)= 4(a²+10a+25)-4a²-40a= 4a²+40a+100-4a²-40a= 100
(2a-b)²-(2a+b)²= (2a-b+2a+b)(2a-b-2a-b)= 4a*(-2b)= -8ab
-8*10/7*7/10= -8
1) 3x(3x+7)-(3x+1)²= 9x²+21x-9x²-6x-1= 15x-1
2) (y-2)(y+3)-(y-1)²= y²+3y-2y-6-y²+2y-1= 3y-7
3) (p+1)²-(p+2)²= p²+2p+1-p²-4p-4= -2p-3
4) 4(a+5)²-(4a²+40a)= 4(a²+10a+25)-4a²-40a= 4a²+40a+100-4a²-40a= 100
(2a-b)²-(2a+b)²= (2a-b+2a+b)(2a-b-2a-b)= 4a*(-2b)= -8ab
-8*10/7*7/10= -8