\(7x\left(2+x\right)-7x\left(x+3\right)=14\)
\(\Leftrightarrow14x+7x^2-7x^2-21x=14\)
\(\Leftrightarrow\left(14x-21x\right)+\left(7x^2-7x^2\right)=14\)
\(\Leftrightarrow-7x+0=14\)
\(\Leftrightarrow-7x=14\)
\(\Leftrightarrow x=14\div\left(-7\right)\)
\(\Leftrightarrow x=-2\)
Vậy x = - 2
Trả lời.............
X=-2
...................học tốt...................
Trả lời.................
X=-2
...................học tốt.....................
Trả lời...............
X=-2
.......................học tốt.......................
\(7x\left(2+x\right)-7x\left(x+3\right)=14\)
\(\Leftrightarrow7x\left(2+x-x-3\right)=14\)
\(\Leftrightarrow7x\left(-1\right)=14\)
\(\Leftrightarrow-7x=14\Leftrightarrow x=-2\)
mik thay cach lam cua bam Tran Minh Phong de hieu hon
