How do you solve the system of equations below and give your answer as an ordered pair: 4x + 7y = 47 and 5x - 4y= -5?

1 Answer
Jan 16, 2018

(3,5)

Explanation:

5x - 4y = -5

5x = 4y - 5

x = (4y)/5 - 1

So we can substitute that into the equation 4x + 7y = 47 to get:

4((4y)/5 - 1) + 7y = 47

(16y)/5 - 4 + 7y = 47

(16y)/5 + 7y = 51

(16y)/5 + (35y)/5 = 51

(51y)/5 = 51

51y = 255

y = 5

By plugging y back into either of the original equations, we can solve for x:

5x - 4(5) = -5

5x - 20 = -5

5x = 15

x = 3

Now that you have x and y, you would write out the ordered pair in the form (x,y): (3,5)