Question

4. Adam used elimination to solve the system of equations to the right and found the solution x=9. What is the corresponding value for y that creates the solution to the system?

Answer 1

Since Adam has already found the value of x, We just need to replace x into any of the equations and solve for y. So, let's replace the value of x into the 1st equation:

`\begin{gathered} -4x+9y=9 \\ -4(9)+9y=9 \\ -36+9y=9 \end{gathered}`

Add 36 to both sides:

`\begin{gathered} -36+9y+36=9+36 \\ 9y=45 \end{gathered}`

Divide both sides by 9:

`\begin{gathered} (9y)/(9)=(45)/(9) \\ y=5 \end{gathered}`

Answer:

y = 5