Question

Mă poate ajuta cineva.[(y+90)×7-100]÷4÷5=30

Answer 1

[(y+90)×7-100]÷4÷5=30
(7y+630-100)÷4÷5=30
7y+530=30×4×5
7y+530=120×5
7y+530=600
7y=600-530
7y=70
y=70÷7
y=10

Answer 2

[(y+90)×7-100]÷4÷5=30

[(y+90)×7-100]=A
A:4:5=30
A=30*5*4=600

[(y+90)×7-100]=600
7Y+630=700
7Y=700-630
7Y=70
Y=10