Question

a² + 4a (para a=2/3)

Answer 1

$\frac{a2 {}^{2} }{3} + 4a \\ \\ \\ \frac{a4}{9} + 4a \\ \\ \frac{8a}{9}$

Answer 2

$( { \frac{2}{3} })^{2} + 4 \frac{2}{3} = \frac{4}{9} + \frac{8}{3} = \frac{12 + 72}{27} = \frac{84}{27} = \frac{28}{9}$