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2x — Зу = 21
5x - 2y = 25
Elimination using multiplication

User Jon Story
by
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1 Answer

2 votes

Answer:

(3, -5)

x = 3

y = -5

Explanation:

Multiply the entirety of the equations by a number so that they have one variable that has the same coefficient.

Multiply so that both equations will have "6y".

2x — Зу = 21 X2 ==> 4x - 6y = 42

5x - 2y = 25 X3 ==> 15x - 6y = 75

When you subtract a number from the same number, it becomes 0. (-6y) - (-6y) = 0, eliminating one of the variables so you can solve for "x".

Subtract the equation on the bottom from the equation on the top:

. 15x - 6y = 75

- 4x - 6y = 42 Subtract each of the terms.

. 11x = 33 Divide both sides by 11 to isolate x.

. x = 3

Substitute x = 3 into any of the equations.

2x - Зу = 21

2(3) - 3y = 21 Simplify

6 - 3y = 21 Start isolating y.

-3y = 21 - 6 Subtract 6 from both sides.

-3y = 15 Divide both sides by -3.

y = -5

A point is in the form (x, y).

The solution to this system is (3, -5) or x = 3 y = -5.

User Krunal Panchal
by
4.7k points