Question

Mihai a cheltuit o suma de bani in doua zile.in prima zi mihai a cheltuit 30%din sumă,iar a doua zi si restul de 35 de lei .Calculati suma de bani cheltuiti de Mihai in prima zi.

Answer 1

notam suma cheltuita in total=,,a"
I zi=30a/100
a II zi=35

30a/100+35=a
numitor comun 100
(30a+3500)/100=100a/100
inmultim totul cu 100
30a+3500=100a
3500=100a-30a
70a=3500
a=3500:70
a=50
a doua zi cheltuie 35
prima zi cheltuie 50-35=15