Answer
a. $8$
b. $8$ is not a solution of the equation
Work Step by Step
$a.$
Replace x with $3$ and y with $\displaystyle \frac{1}{2}$:
$5x-14y=$
$=5\displaystyle \cdot 3-14\cdot\frac{1}{2}$
$=15-7$
$=8$
b.
If the number $8$ is the solution to the equation, then replacing $w$ with $8$ should result in a valid equation (the left side should be equal to the right side of the equality sign)
$4w=54-5w\quad?$
$4(8)=54-5(8)\quad?$
$32=54-40\quad?$
No, the equation is not valid, $8$ is not a solution of the equation.
