Math Problem Statement

negative x plus y equals negative 2 4 x plus y equals negative 7

Solution

You have the following system of linear equations:

  1. x+y=2-x + y = -2
  2. 4x+y=74x + y = -7

Let's solve this system using the substitution or elimination method. I’ll use the substitution method here.

Step 1: Solve one equation for one variable

From the first equation x+y=2-x + y = -2, we can solve for yy:

y=x2y = x - 2

Step 2: Substitute into the second equation

Now, substitute y=x2y = x - 2 into the second equation 4x+y=74x + y = -7:

4x+(x2)=74x + (x - 2) = -7

Step 3: Solve for xx

Simplify the equation:

4x+x2=74x + x - 2 = -7

5x2=75x - 2 = -7

Add 2 to both sides:

5x=55x = -5

Now, divide both sides by 5:

x=1x = -1

Step 4: Substitute x=1x = -1 back into the equation for yy

Now, substitute x=1x = -1 into y=x2y = x - 2:

y=12=3y = -1 - 2 = -3

Final Answer:

The solution is x=1x = -1 and y=3y = -3.

Verification:

Substitute x=1x = -1 and y=3y = -3 into both original equations to verify:

  • For the first equation: (1)+(3)=13=2-(-1) + (-3) = 1 - 3 = -2 (correct)
  • For the second equation: 4(1)+(3)=43=74(-1) + (-3) = -4 - 3 = -7 (correct)

Both are satisfied, so the solution is correct.


Would you like to see more steps or have questions on this solution?

Here are some related questions:

  1. How would you solve the system using the elimination method?
  2. What would happen if we multiplied one of the equations by a constant before solving?
  3. How do you solve a system of equations if one of the equations is a fraction?
  4. What is the graphical interpretation of the solution to this system of equations?
  5. How can this method be extended to solve systems with three variables?

Tip: If you can easily express one variable in terms of the other (like we did with y=x2y = x - 2), substitution is often the quickest method!

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Math Problem Analysis

Mathematical Concepts

Linear Equations
Algebra
Substitution Method
Systems of Equations

Formulas

y = x - 2
4x + y = -7
-x + y = -2

Theorems

Substitution Method for Solving Systems of Equations

Suitable Grade Level

Grades 8-10