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5 votes
4x-3y=19
y=3x-13

X=
Y=

User Silverkid
by
7.6k points

1 Answer

4 votes

Answer:

x = 4

y = -1

Explanation:

This is a reasonably simple question, as it just requires us to substitute and rearrange the values

substitute the given value of y (the second equation) into the first equation. this allows the equation to only have one unknown (x)

4x - 3y = 19

y = 3x - 13

4x - 3(3x - 13) = 19

expand out the bracket using the distributive law (let me know if you aren't familiar with this)

4x - 9x + 39 = 19

subtract 39 from both sides and combine like terms

4x - 9x + 39 = 19

-5x + 39 = 19

-5x = 19 - 39

-5x = -20

divide both sides by -5 to get x on its own:


(-5x)/(-5) =
(-20)/(-5)

x = 4

we have now solved the equations together to find the value of x. we can now substitute this into either equation to solve for y. I will use the second as it has already been arranged to have y as the subject.

y = 3x - 13

y = 3(4) - 13

y = 12 - 13

y = -1

therefore x = 4 and y = -1

to test this you can substitute both these values into either one of the equations to see if they are correct.

hope this helps :)

User MangoHands
by
7.4k points