Question

Façam a conta passo a passo, obrigada!

Answer 1

$\large\boxed{\begin{array}{l} \rm \dfrac{A}{20} = \dfrac{6}{30} \\ \\ \rm \:30A = 6 \times 20 \\ \\ \rm \: 30A = 120 \\ \\ \rm \: A = \dfrac{120}{30} \\ \\ \boxed{\rm A = 4} \\ \\ \rm \dfrac{4}{B} = \dfrac{3}{21} \\ \\ \rm \: 3B = 21 \times 4 \\ \\ \rm \: 3B = 84 \\ \\ \rm \: B = \dfrac{84}{3} \\ \\ \boxed{ \rm{B = 28}} \\ \\ \\ \rm \: A+B = 4 + 28 \\ \\ \boxed{ \boxed{ \rm{A+B = 32}}} \leftarrow \textsf{Letra B}\end{array}}$