Question

afla necunoscuta [(38×a+120)÷25×54]-980=100

Answer 1

[(38xa+120):25x54]-980=100
[(38xa+120):25x54]=100+980
(38xa+120):25x54=1080
(38xa+120):25=1080:54
(38xa+120):25=20
(38xa+120)=20x25
38xa+120=500
38xa=500-120
38xa=380
a=380:38
a=10

Answer 2

[(38xb+120):25x54]-980=100
[(38xb+120):25x54]=100+980
(38xb+120):25x54=1080
(38xb+120):25=1080:54
(38xb+120):25=20
(38xb+120)=20x25
38xb+120=500
38xb=500-120
38xb=380
b=380:38
b=10
In loc de a am pus b dar poti inlocui si singur :)))