The first step in solving using the substitution method is making an unknown value the subject of the formula.
The substitution method is one of the methods that is used to solve simultaneous equations. It involves making one unknown value the subject of the formula.
For example, given these simultaneous equations:
a + b = 10
2a + 5b = 20
The first step is to make either a or b the subject of the formula
a = 10 - b
or
b = 10 - a
To learn more about simultaneous equations, please check: https://brainly.com/question/25875552
