2+10+9+7+7=3x+4x
=>3x+4x=35
=>7x=35
=>x=35:7
=>x=5
2+10+9+7+7=3x+4x
\(\Rightarrow\)3x+4x=35
x.(3+4)=35
x.7=35
x=35:7
x=5
Suy ra: 3x+4x=35
7x =35
x=35:7
x=5
k cho minh
2 + 10 + 9 + 7 + 7 = 3x + 4x
35 = x.(3+4)
35 = 7x
=> x = 35 : 7
=> x = 5
2 + 10 + 9 + 7 + 7 = 3x + 4x
35 = x.(3+4)
35 = 7x
=> x = 35 : 7
=> x = 5