Question

sabendo que a+b=18 e a-b=2 calcule:
a) (a+b)²
b) (a-b)²
c) a²-b²

Answer 1

$a + b = 18$
$a - b = 2$

a)
$(a + b)^2 = 18^2$

$(a + b)^2 = 324$

b)
$(a - b)^2 = 2^2$

$(a - b)^2 = 4$

c)
$a^2 - b^2 = (a+b)(a-b)$

$a^2 - b^2 = 18.2$

$a^2 - b^2 = 36$