Math Problem Statement

Solve the system by substitution. -7x - 2y = -38 -3y = x

Solution

Let's solve the system of equations by substitution. The system is:

7x2y=38-7x - 2y = -38 3y=x-3y = x

Step 1: Express xx in terms of yy

From the second equation, we already have x=3yx = -3y.

Step 2: Substitute x=3yx = -3y into the first equation

Substitute x=3yx = -3y into the first equation 7x2y=38-7x - 2y = -38:

7(3y)2y=38-7(-3y) - 2y = -38

Simplify the expression:

21y2y=3821y - 2y = -38

19y=3819y = -38

Step 3: Solve for yy

Divide both sides by 19:

y=3819=2y = \frac{-38}{19} = -2

Step 4: Substitute y=2y = -2 into x=3yx = -3y

Now, substitute y=2y = -2 into x=3yx = -3y:

x=3(2)=6x = -3(-2) = 6

Solution:

The solution to the system is x=6x = 6 and y=2y = -2, or (6,2)(6, -2).

Would you like further details or explanations on any step?


Here are some related questions to deepen your understanding:

  1. How do you graphically interpret the solution of a system of linear equations?
  2. What is the method of substitution, and when is it preferable over elimination?
  3. How would the solution change if the second equation was 3y=x3y = x instead of 3y=x-3y = x?
  4. What is the significance of having one solution, infinitely many solutions, or no solutions in a system of equations?
  5. How can you check if the solution (6,2)(6, -2) satisfies both equations?

Tip: Always substitute your solution back into the original equations to verify its correctness.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Equations
Substitution Method

Formulas

x = -3y
Substitution of one equation into another to solve for variables

Theorems

Substitution Method

Suitable Grade Level

Grades 9-12