Question

1 calcule os produtos

a)(5+a)²
b)(2x-3)²
c)(y+5)²
d)(2b-7)²
e)(x+3)(x-3)
f) (x•5)(x+5)​

Answer 1

Resposta:

$a)\\ \\ (5+a)^{2} =5^{2}+2.5.a+a^{2}=a^{2} +10a+25\\ \\ b)\\ \\ (2x-3)^{2} =(2x)^{2} -2.2x.3+3^{2} =4x^{2} -12x+9\\ \\ c)\\ \\ (y+5)^{2} =y^{2} +2.y.5+5^{2} =y^{2} +10y+25$

$d)\\ \\ (2b-7)^{2} =(2b)^{2} -2.2b.7+7^{2} =4b^{2} -28b+49\\ \\ e)\\ \\ (x+3)(x-3)=x^{2} -3^{2} =x^{2} -9\\ \\ f)\\ \\ (x~.~5)(x+5)=5x(x+5)=5x^{2} +25x$