Email us to get an instant 20% discount on highly effective K-12 Math & English kwizNET Programs!

#### Online Quiz (WorksheetABCD)

Questions Per Quiz = 2 4 6 8 10

### High School Mathematics1.21 Linear Equations in Two Variables- Solving by the Method of Substitution

 Method: Solve one of the equations for one variable in terms of the other. Substitute that expression found in step 1 into the other equation to obtain an equation in one variable. Solve the equation obtained in step 2 Back substitute the solution in step 3 into the expression obtained in step 1 to find the value of the other variable Check that the solution satisfies each of the original equations Example: Solve the same system of equations by the method of substitution. 2x + y = 4 ----- Equation 1 x − y = −1 ------- Equation 2 Solution: Take equation 1: 2x + y = 4 ----- Equation 1 2x + y = 4 y = 4 - 2x Substituting y in equation 2 x − y = −1 ------- Equation 2 x − (4 − 2x) = −1 Solving for x x − 4 + 2x = −1 3x = −1 + 4 3x = 3 x = 1 To find y, substitute x = 1 in equation 1 2x + y = 4 ----- Equation 1 2x + y = 4 2(1) + y = 4 2 + y = 4 y = 4 - 2 y = 2 x = 1 and y = 2 Answer: (1,2) Directions: Solve the linear equations by the method of substitution. Also write at least 5 examples of your own.
 Q 1: Solve the system by the method of substitution 2y + x = 3 4y – 3x = 1 inconsistant(1,1)(0,2)(1,7) Question 2: This question is available to subscribers only!