Question

(у-4)во второй степени; (7х+а)во второй степени; (5с-1)(5с+1); (3а+2b)(3a-2b)

Answer 1

$(y-4)^2=y^2-2*y*4+4^2=y^2-8y+16$

$(7x+a)^2=(7x)^2+2*7x*a+a^2=49x^2+14xa+a^2$

$(5c-1)(5c+1)=(5c)^2-1^2=25c^2-1$

$(3a+2b)(3a-2b)=(3a)^2-(2b)^2=9a^2-4b^2$

Answer 2

(y-4)^2=(y+4)(y-4)

(7x+a)^2=(7x+a)(7x-a)

(5c-a)(5c+1)=(5c-a)^2

(3a+2b)(3a-2b)=(3a-2b)^2