Question

sabendo que a + b= 18 e a-b=2, calcule o valor de a^2-b^2

Answer 1

a+b=18
a-b=2

a=2+b

2+b+b=18
2b=18-2
2b=16
b=16/2
b=8

a-b=2
a-8=2
a=8+2
a=10

$a^{2} = 10^{2} = 100$

$b^{2} = 8^{2} = 64$

100-64=  46