X x 45 + X x 54 + X = 700
X x ( 45+ 54+ 1 ) =700
X x 100 =700
X =700 : 100
X =7
\(x\times45+x\times54+x=700\)
\(\Leftrightarrow x\times\left(45+54+1\right)=700\)
\(\Leftrightarrow x\times100=700\)
\(\Leftrightarrow x=7\)
Vậy \(x=7\)
X x 45 + X x 54 +X = 700
X x 45 + X x 54 +X x 1 = 700
X x ( 45 + 54 + 1 ) = 700
X x 100 = 700
X = 700 : 100
X = 7
Hok tốt ^^