Question

4/5*c-7/15*c+1/3*c=3/5

Answer 1

$frac{4}{5} c - frac{7}{15} c = frac{12}{15} c - frac{7}{15} c = frac{5}{15} c = frac{1}{3} c$
$frac{1}{3} c + frac{1}{3} c = frac{2}{3} c$
$frac{2}{3} c = frac{3}{5} \ c = frac{3}{5} div frac{2}{3} = frac{3}{5 } times frac{3}{2}$
$c = frac{9}{10} = 0.9$