Question

помогите пожалуйста.​

Answer 1

1)  $\displaystyle (3b-5)^2-49= (3b-5)^2-7^2=(3b-5-7)(3b-5+7) = (3b-12)(3b+2) = 3(b-4)(3b+2)$

2) $\displaystyle (2x-3)^2-(x+4)^2=(2x-3-x-4)(2x-3+x+4)=(x-7)(3x+1)$

3) $\displaystyle a^4-(a-7)^2=(a^2)^2-(a-7)^2=(a^2-a+7)(a^2+a-7)$

4) $\displaystyle (a-b+c)^2-(a-b-c)^2=(a-b+c-a+b+c)(a-b+c+a-b-c) = 2c*(2a-2b)=4c*(a-b)$