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

Answer:

(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)