Question

calcule o valor numérico da expressão

Answer 1

$\frac{3}{4}.a^2.b - \frac{5}{6}.a.b^2 - \frac{1}{2} \\\\a) a=0; b=-1 \\= \frac{3}{4}.0^2.(-1) - \frac{5}{6}.0.(-1)^2 - \frac{1}{2} = 0 - 0 - \frac{1}{2}= \frac{1}{2}\\\\b)a=-1;b= \frac{1}{3} \\= \frac{3}{4}.(-1)^2. \frac{1}{3} - \frac{5}{6}.(-1).(\frac{1}{3})^2 - \frac{1}{2} \\\\= \frac{3}{4}.1. \frac{1}{3} - \frac{5}{6}.(-1).\frac{1}{9} - \frac{1}{2}\\\\=\frac{3.1.1}{4.3} -( \frac{5.(-1).1}{6.9}) - \frac{1}{2}\\\\=\frac{3}{12} -( -\frac{5}{54}) - \frac{1}{2}$
$= \frac{3}{12} -( -\frac{5}{54}) - \frac{1}{2}\\\\ = \frac{3}{12} +\frac{5}{54} - \frac{1}{2}\\\\ = \frac{9.3 + 2.5 - 54.1}{108}\\\\= \frac{27 + 10 - 54}{108}\\\\= -\frac{17}{108}$
bons estudos!!