Question

sa se rezolve ecuatia |x+1|+|3x+3|=8

Answer 1

|x+1|+|3x+3|=8

|x+1|+|3(x+1)|=8

|x+1|+3 × | x +1|=8

4x |x+1|=8

|x+1|=2

x+1=2

x+1=-2

x=1

x=-3

Answer 2

$\it |x + 1|+|3x+1|=8 \Rightarrow |x+1|+3|x+1|=8\ \ \ \ (1)\\ \\ \\ Dac\breve{a}\ notez\ |x+1|=t \Rightarrow t+3t=8 \Rightarrow 4t=8 \Rightarrow t=2\\ \\ \\ |x+1| =2 \Rightarrowx+1=\pm2 \Rightarrow x+1\in\{-2,\ 2\}|_{-1} \Rightarrow x\in\{-3,\ 1\}$