Question

Daca a:b=2, atunci (a^2-b^2) : ab

Answer 1

a : b = 2, a = 2b
(4b² - b²) : 2b×b = 3b² : 2b² = 3/2 = 1,5

Answer 2

$\frac{a}{b} =2 \\ a=2b \\ \frac{2b*2b- b^{2} }{2b*b} = \frac{ 4b^{2}- b^{2} }{ 2b^{2} } = \frac{ 3b^{2} }{ 2b^{2} } = \frac{3}{2} =1.5$