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2 years ago

-3x + y = -14 x= -2y + 14 Which variable should an expression be substitute for?

Mathematics

1 answer:

ICE Princess25 [194]2 years ago

3 0

9514 1404 393

Answer:

Step-by-step explanation:

There is already an expression given for x, so that is the easiest variable to substitute for.

Substituting for x using the second equation, you have ...

-3(-2y+14) +y = -14

6y -42 +y = -14

7y = 28

y = 4

x = -2(4) +14 = 6

The solution is (x, y) = (6, 4).

_____

Substitution for x is the easiest.

The first equation could be rearranged to give an expression for y:

y = 3x -14

Then that can be used to substitute for y in the second equation. My lazy brain judges that to be more work.

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