For 15 points. Explain, in your own words, the steps necessary to solve a system of equations using the substitution method.

First, what is an equation?

➳ A mathematical statement which shows that two algebraic expressions are equal is called and equation.

Or, LHS = RHS

Example:- 3x - 5 = x + 8

An equation is said to be a linear equation if it contains only one variable (literal) with highest power 1.

_______________________

Solving an equation:-

To solve the equation x + 5 = 7 means to find the value of an unknown algebraic quantity used in the equation.

Example:-

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

★ Rules for solving an equation by the substitution method:-

Rule ❶ 

If x = 2, the value of the expression 3x + 2 = 3 × 2 + 2 = 6 + 2 = 8

Rule ❷

If x = 0, the value of the expression 3x + 2 = 3 × 0 + 2 = 0 + 2 = 2

Rule ❸ 

If x = -2, the value of the expression 3x + 2 = 3 × -2 + 2 = -6 + 2 = -4

Now consider the algebraic expression 5x - 2y

This expression consists of variables x and y.

Now if :-

⠀⠀⠀⠀⠀⠀⠀⠀

The process of finding the value of an algebraic expression by substituting the given value of its variable is called substitution.⠀⠀

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.