Question

(X+X+X+20):2=25

tìm X

Answer 1

=>3x+20=50

hay x=10

Answer 2

=>3x+20=50

hay x=10

Answer 3

x+x+x+20      =25x2

x+x+x+20      =50

x+x+x            = 50-20

x+x+x            =30

Vậy x=10 vì 10+10+10=30

Answer 4

x=10

Answer 5

x+x+x+20      =25x2

x+x+x+20      =50

x+x+x            = 50-20

x+x+x            =30

Vậy x=10 vì 10+10+10=30