Question

Multiply each equation by a constant that wold help eliminate the y terms

2x-5y=-21
3x-3y=-18

Answer 1

x=-3, y=3. (-3, 3).

Explanation:

2x-5y=-21

3x-3y=-18

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simplify 3x-3y=-18 into x-y=-6

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2x-5y=-21

x-y=-6

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x=y+(-6)

x=y-6

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2(y-6)-5y=-21

2y-12-5y=-21

-3y-12=-21

-3y=-21+12

-3y=-9

3y=9

y=9/3

y=3

x=3-6=-3

Answer 2

-3 and 5

Explanation:

I would first start by picking a variable to cancel out (either the x or the y).

Let's suppose that you choose to eliminate the x value. Since you are adding the two equations, you need both coefficients of the x values to cancel out, having one be positive and one be negative.

The first equation would be multiplied by -3:

-3(2x - 5y = -21) = -6x + 15y = 63

The second equation would be multiplied by 2:

2(3x - 3y = -18) = 6x - 6y = -36

Therefore, if you do this to eliminate the y terms:

-3(2x - 5y = -21) = -6x + 15y = 63

5(3x - 3y = -18) = 15x - 15y = 90