How can we solve the system of equations 2x + 5y = 13 and 3x + 4y = 8?

To solve the system of equations given by 2x + 5y = 13 and 3x + 4y = 8, we can use either the substitution method or the elimination method. Here, we will use the elimination method to find the values of x and y.

Step 1: Align the equations

We have the two equations:

  • Equation 1: 2x + 5y = 13
  • Equation 2: 3x + 4y = 8

Step 2: Make the coefficients of one variable the same

To eliminate y, we can manipulate the equations to make the coefficients of y equal. We will multiply the first equation by 4 and the second equation by 5:

  • Equation 1 multiplied by 4: 8x + 20y = 52
  • Equation 2 multiplied by 5: 15x + 20y = 40

Step 3: Subtract the equations

Now, we can subtract the first modified equation from the second:

(15x + 20y) – (8x + 20y) = 40 – 52

This simplifies to:

7x = -12

Now, we can isolate x:

x = -12 / 7
x = -1.7142857

Step 4: Substitute x back into one of the original equations

We’ll substitute x = -12/7 into the first original equation:

2(-12/7) + 5y = 13

This simplifies to:

-24/7 + 5y = 13

To eliminate the fraction, we can multiply all terms by 7:

-24 + 35y = 91

35y = 91 + 24

35y = 115

y = 115 / 35

y = 3.2857143

Step 5: Final solution

Thus, the solution to the system of equations is:

  • x ≈ -1.71
  • y ≈ 3.29

We have now successfully solved the system of equations!

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