Question

Giúp mk lm câu 3 vs ạ

Answer 1

Câu I:

1: Ta có: 4x-3=2x+7

nên 2x=10

hay x=5

2: Ta có: \(\left|x-2\right|=4-2x\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=4-2x\left(x\ge2\right)\\x-2=2x-4\left(x< 2\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=6\\-x=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\left(nhận\right)\\x=2\left(loại\right)\end{matrix}\right.\)

3: ta có: \(\left(x-1\right)\left(x-2\right)\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=2\\x=-1\end{matrix}\right.\)

Answer 2

Nhóm 1:(45+15):2=30

lớp 8A có 30 Hs trồng hoa