Question

afla nr necunoscut . {[(a+25)×9-18]÷10+3}×5=150

Answer 1

{[(a+25)×9-18]÷10+3}×5=150
{[(a+25)×9-18]÷10+3}=150:5
[(a+25)×9-18]÷10+3=30
[(a+25)×9-18]÷10=30-3
[(a+25)×9-18]÷10=27
[(a+25)×9-18]=27x10
(a+25)×9-18=270
(a+25)×9=270+18
(a+25)×9=288
a+25=288:9
a+25=32
a=32-25
a=7