x.5+x.6-x.7=78x12
x.(5+6-7)=78x12
x.4=936
x =936:4
x =234
X x ( 5 + 6 - 7 ) = 936
X x 4 = 936
X = 936 : 4
X = 234
\(x\cdot5+x\cdot6-x\cdot7=78\cdot12\)
\(\Leftrightarrow x\left(5+6-7\right)=936\)
\(\Leftrightarrow4x=936\)
\(\Leftrightarrow x=234\)
X x 5 + X x 6 - X x 7 = 78 x 12
X x 5 + X x 6 - X x 7 = 936
X x (5+6-7)=936
X x 4 = 936
X = 936 : 4
X = 234
đúng cho mình nhé
X *5+x *6-X*7=78x12
X *(5+6-7) =936
X *4 =936
X =936:4
X = 234
Hay tk cho mk nhé!Cảm ơn các bạn!