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Just need an explanation for this.

Just need an explanation for this.-example-1

2 Answers

2 votes

Answer/Step-by-step explanation:

These equations are set up to solve using the method called Substitution.

The second equation:

x = -2y + 12

is already set equal to x. So we can see that x is exactly -2y+12. So we are going to stuff -2y+12 in place of x in the first equation.

1st eq: 6x - 4y = 8

replace x with -2y+12.

Like this:

6(-2y+12) - 4y = 8

use distributive property

-12y + 72 - 4y = 8

combine like terms

-16y + 72 = 8

subtract 72 from both sides

-16y = -64

divide both sides by -16

y = 4

Now use y=4 in either equation (or both to do a check) to find x.

x = -2y + 12

x = -2(4) + 12

x = -8 + 12

x = 4

So, x = 4 and y = 4, we can write this as (4,4)

To check we can do the calculation for x in the other equation:

6x - 4y = 8

6x - 4(4) = 8

6x - 16 = 8

Add 16

6x = 24

Divide by 6

x = 4

check!

The solution is (4,4)

answered
User SaAtomic
by
7.7k points
4 votes

Explanation:

Since x = -2y + 12 put that in for 'x' in the first equation

6 ( -2y+12) - 4y = 8

-12y + 72 -4y = 8

-16y = -64

y = 4 then x = - 2y+12 = -2(4) +12 = 4

(4,4)

answered
User Matthew Walker
by
8.5k points

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