Question

(a-b)×(a+b), quando a=1 e
$b = \frac{ 3}{4}$

Answer 1

$(1 - \frac{3}{4} )(1 + \frac{3}{4} ) = {1}^{2} - ( { \frac{3}{4} })^{2} = \\ = 1 - \frac{9}{16} = \frac{16}{16} - \frac{9}{16} = \frac{7}{16}$