Question

5x-7 ; 3x ; 3x+1 , termeni consecutivi a unei p.a. Aflați X . ​

Answer 1

3x=((5x-7)+(3x+1))/2
3x=(5x-7+3x+1)/2
2*3x=8x-6
6x=8x-6
6x-8x=-6
-2x=-6
X=(-6):(-2)
X=3

Answer 2

$\it \dfrac{5x-7+3x+1}{2}=3x \Rightarrow 8x-6=6x \Rightarrow 8x-6x=6 \Rightarrow 2x=6 \Rightarrow x=3$