x : 0,25 + x : 0,125 = 120
=> x : 1/4 + x : 1/8 = 120
=> x * 4 + x * 8 = 120
=> x * (4 + 8) = 120
=> x * 12 = 120
=> x = 120 : 12
=> x = 10.
x:0,25+x:0,125=120
x:1/4+x:1/8=120
x.4+x.8=120
x(4+8)=120
x.12=120
x=120:12
x=10
x:0,25+x:0,125=120
x:1/4+x:1/8=120
x.4+x.8=120
x(4+8)=120
x.12=120
x=120:12
x=10
tick nhé