Explain how to solve the equation 7s=28

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1

Place the following steps in order to complete the square and solve the quadratic equation,