How to do system of equations

The three methods most commonly used to solve systems of equation are substitution, elimination and augmented matrices.

Step-by-step explanation:

Substitution is a method of solving systems of equations by removing all but one of the variables in one of the equations and then solving that equation.

Elimination is another way to solve systems of equations by rewriting one of the equations in terms of only one variable. The elimination method achieves this by adding or subtracting equations from each other in order to cancel out one of the variables.

Augmented matrices can also be used to solve systems of equations. The augmented matrix consists of rows for each equation, columns for each variable, and an augmented column that contains the constant term on the other side of the equation.

the solution is h=10 because you add 9 to each side of the equation.