Answer
true for all values of $x$.
Work Step by Step
$y_{1}=2x + 6$ equation 1
$y_{2}=x + 8$ equation 2
$y_{3}=x$ equation 3
$3y_{1}-5y_{2} =y_{3}-22$ --> equation 4
Substitute equations 1 , 2 & 3 to equation 4:
$3y_{1}-5y_{2} =y_{3}-22$
$3(2x + 6)-5(x + 8) =x-22$
Expand $3(2x + 6)$ = $6x+18$
Expand $5(x + 8)$ = $5x+40$
Rewrite the equation:
$6x+18-(5x+40)=x-22$
$6x+18-5x-40=x-22$
$x-22=x-22$
Since both sides are equal, then the equation is true for all values of $x$.