Question

If x + 4y = 18 and x - 4y = 2, then y = ?A) 2B) 4C) 10D) no solution

Answer 1

The value of y is 2

$\begin{gathered} x\text{ + 4y = 18} \\ x\text{ - 4y = 2} \end{gathered}$

We can subtract the two equations to get y

$\begin{gathered} x\text{ + 4y =18} \\ -(x-4y=2) \end{gathered}$$\begin{gathered} 8y\text{ = 16} \\ y\text{ = 2} \end{gathered}$