Question

dupa ce a cheltuit 1/5 din suma pe care o avea si inca 15,6 lei, Ionel a ramas cu jumatate din suma initiala. Ce suma a avut Ionel la inceput?

Answer 1

Notam a=suma initiala
1/5×a+15,6=2,5/5×a
15,6=2,5a/5-1a/5=1,5/5×a
0,5a/5=15,6/3=5,2
a=5,2(0,5a/5)×10= 5/5 a=1a=52

Answer 2

$x - suma \: initiala$

$\frac{1}{5} \times x + 15.6 = \frac{x}{2}$

$\frac{x}{5} + 15.6 = \frac{x}{2} \: | \times 10$

$2x + 156 = 5x$

$5x - 2x = 156$

$3x = 156 \: | \div 3$

$x = 52 \: lei$