Math Problem Statement

solve linear systems by subsitution: x-3y=10 x+5y=-22

Solution

Let's solve the system of equations using the substitution method. The given system is:

  1. x3y=10x - 3y = 10
  2. x+5y=22x + 5y = -22

Step 1: Solve one equation for one variable.

We'll start by solving the first equation for xx:

x3y=10(Equation 1)x - 3y = 10 \quad \text{(Equation 1)}

Solve for xx:

x=3y+10x = 3y + 10

Step 2: Substitute the expression for xx into the second equation.

Now, substitute x=3y+10x = 3y + 10 into the second equation:

x+5y=22(Equation 2)x + 5y = -22 \quad \text{(Equation 2)}

Substitute xx in:

(3y+10)+5y=22(3y + 10) + 5y = -22

Step 3: Simplify and solve for yy.

Now combine like terms:

3y+5y+10=223y + 5y + 10 = -22

8y+10=228y + 10 = -22

Now, subtract 10 from both sides:

8y=328y = -32

Finally, divide by 8:

y=4y = -4

Step 4: Substitute y=4y = -4 back into the expression for xx.

Now substitute y=4y = -4 into x=3y+10x = 3y + 10:

x=3(4)+10x = 3(-4) + 10

x=12+10x = -12 + 10

x=2x = -2

Final Answer:

The solution to the system of equations is x=2x = -2 and y=4y = -4.

Verification:

Let's substitute x=2x = -2 and y=4y = -4 into the original equations to verify:

  1. x3y=23(4)=2+12=10x - 3y = -2 - 3(-4) = -2 + 12 = 10 (True)
  2. x+5y=2+5(4)=220=22x + 5y = -2 + 5(-4) = -2 - 20 = -22 (True)

Thus, the solution is correct: x=2x = -2, y=4y = -4.


Would you like any further details on this method or have any questions?

Related Questions:

  1. How would the method change if the system involved three equations?
  2. What happens if there are infinite solutions or no solution in a system?
  3. How can substitution be used with fractional coefficients?
  4. What is the graphical interpretation of the solution to a system of equations?
  5. How would you solve a system using the elimination method instead of substitution?

Tip:

To make substitution easier, always choose the equation that allows for easier isolation of a variable, such as one with a coefficient of 1 or -1.

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Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Equations
Substitution Method

Formulas

x = 3y + 10

Theorems

Substitution Method for Solving Systems of Linear Equations

Suitable Grade Level

Grades 8-10