X=4y+7 2x-6y=12 System of equations using substitution

Mathematics

1 answer:

Sonja [21]2 years ago

7 0

Answer:

x=3, y=-1

Step-by-step explanation:

We are already given an equation solved for x, making substitution much easier. We know x=4y+7, meaning we can put 4y+7 whenever we see x in the second equation

2x-6y=12

We substitute 4y+7 in place of x

2(4y+7)-6y=12

Now we only have one variable to work on, distribute the 2

8y+14-6y=12

Combine similar terms, 8y-6y=2y

2y+14=12

Subtract 14 from both sides

2y=-2

y=-1

Now we plug in -1 for y in the first equation to find x

x=4(-1)+7

x=-4+7

x=3

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