How do you solve x = 4y and 2x + 3y = 44 using substitution?

2 Answers
jim p.
Jun 1, 2018

You have x = 4y, so, what you do is, substitute 4y wherever you see x in the second equation. This sequence looks like:

2x + 3y = 44

2(4y) + 3y = 44

8y + 3y = 44

11y = 44

y = 44/11 = 4

...now that you know that y = 4, you can plug this in to either equation and solve for x.

x = 4y = 4(4)

x = 16

CHECK YOUR WORK. Feed these values into each equation to verify that they are actually solutions.

x = 4y
16 = 4 * 4 CHECK

2x + 3y = 44

(2 * 16 ) + (3 * 4) = 32 + 12 = 44 CHECK

GOOD LUCK

Jim G.
Jun 1, 2018

(x,y)to(16,4)

Explanation:

x=4yto(1)

2x+3y=44to(2)

color(blue)"substitute "x=4y" into equation "(2)

2(4y)+3y=44

8y+3y=44

11y=44rArry=44/11=4

"substitute "y=4" into equation "(1)

x=4xx4=16

"point of intersection "=(16,4)

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