1)(x-2)^2-(x-7)(7+x) 2)(10+x)(x-+3)^2 3)(9-x)(x+-7)^2 - вопрос №8651455122772103239724323252 от dasha1933 14.08.2020 20:05

Question

Алгебра: 1)(x-2)^2-(x-7)(7+x) 2)(10+x)(x-+3)^2 3)(9-x)(x+-7)^2 4)(3+x)^2-(x-3)^2 5)2•(a+4)^2-(8+x)(x-8)

dasha1933 · Answer

1) (x-2)²-(x-7)(7+x)= x²+4-4x-(x²-49)= x²+4-4x-x²+49= 53-4x
2) (10+x)(x-10)-(x+3)²= x²-100-(x²+9+6x)= x²-100-x²-9-6x=-6x-109
3) (9-x)(x+9)-(x-7)²=81-x²-(x²+49-14x)= 81-x²-x²-49+14x= -2x²+32+14x
4) (3+x)²-(x-3)²= (3+x-(x-3))(3+x+x-3)= (3+x-x+3)*2x= 6*2x=12x
5) 2(a+4)²-(8+x)(x-8)= 2(a²+16+8a)-(x²-64)= 2a²+32+16a-x²+64= 2a²+16a-x²+96