120+x - 10 = 90+100
120+x - 10 = 190
x - 10 = 190-120
x - 10 = 70
x = 70+10
x = 80
k mik nha
\(120+x-10=90+100\)
\(120+x=90+100\)
\(120+x=190\)
\(x-10=190-120\)
\(x-10=70\)
\(x=70+10\)
\(\Rightarrow x=80\)
Đ/s: ...
120 + x - 10 = 90 + 100
120 + x - 10 = 190
x - 10 = 190 - 120
x - 10 = 70
x = 70 + 10
x = 80
120+x-10=90+100
120+x-10=190
120+x =190+10
120+x =200
x =200-120
x. =80
bài đó ra bằng 80 nhớ k cho mình nha
