\(\left(x+5\right)+\left(x+7\right)+\left(x+8\right)=58\)
\(\left(x+x+x\right)+\left(5+7+8\right)=58\)
\(3x+20=58\)
\(3x=58-20\)
\(3x=38\)
\(x=38
:
3\)
\(x=\dfrac{38}{3}\)
(x+5)+(x+7)+(x+8)=58
<=> x+5 + x + 7 + x + 8 = 58
<=> 3x + 20 = 58
<=> 3x = 58-20 = 38
<=> x = \(\dfrac{38}{3}\)