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Solve the system of equations by substitution.

-8x+2y=4
y=4x+2

2 Answers

3 votes

Answer:

the answer by substitution would be y = 4x+2

User Grant Eagon
by
5.3k points
5 votes

Correct answer: Infinite solution because 2 = 2.

Set the first equation equal to y.

-8x + 2y = 4

+8x +8x

___________

2y = 8x + 4

__ ___ __

2 2 2

y = 4x + 2

At this step, you can choose any equation to substitute into the other equation. However, I'm going to substitute the new first equation with the second equation where y is. Solve for x.

y = 4x + 2

4x + 2 = 4x + 2

-4x -4x

____________

2 = 2

So, at this point, we know the system of equation does not have one solution. Thus, when the same number equals the same number, it is an infinite solution.

We can prove this by an online graphing tool. Insert the two equations onto the online graphing tool. If the lines appear to be on the same line, they have infinite solutions. Hope this helps :) Let me know if you have any questions related to this problem!

User Sarsaparilla
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4.6k points