HW #23 Solutions: p. 189 #14-21

No Solution

All ordered pairs that lie on 

the graph of 2y = 4x ­ 6.

No Solution

Aim #24: How do we solve a system of equations algebraically using the substitution method?Homework: HandoutDo Now: Consider the two system of equations below. Verify whether the given ordered pairs are solutions:

(3,4) (2, 2.4) y = x + 1 4x + 5y = 20y = -2x + 10 2x + 6y = 10{ {

Besides solving a system of equations GRAPHICALLY, another method is the SUBSTITUTION METHOD. By replacing one variable with an equivalent expression containing the other variable, you can create a one-variable equation to solve.

Example 1: y = 2x + 1 x - y = 7 Check your solution!

Example 2: 2x + y = 4 2x + 3y = 9

Check your solution!

Solve and check each system algebraically using substitution.

a) y = 4x - 1 b) 3x + y = 5y = - x + 8 3x + y = 81

2

c) y = 2x - 4 d) y = -x + 6-6x + 3y = -12 y = x - 33

4

Sum it Up!

To determine the solution to a system of equations, we have found the solutions ____________ and ____________ using ____________.

How can you verify the solution to a system of equations?

e) y = 0.2x + 10 f) 4x + 3y = 274x + 5y = 35 y = 2x - 1

g) Is (-2,-7) the solution of the following system? Explain.

7y - 4x = 29x = y -5