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Does anyone know how to solve this math equation?

(Solve by Elimination, Substitution, or Matrices)
Thank you !!!

Does anyone know how to solve this math equation? (Solve by Elimination, Substitution-example-1
User Raceyman
by
7.4k points

1 Answer

3 votes

Answer:

x = 8; y = -6

Explanation:

We have a system of equations.


(3(x - 2))/(2) - (y - 2)/(4) = 11


(2(x + 2))/(5) - (y)/(3) = 6

First, let's multiply both sides of each equation by the LCM of both denominators of that equation to eliminate all denominators.

First equation:


8 * (3(x - 2))/(2) - 8 * (y - 2)/(4) = 8 * 11


12(x - 2) - 2(y - 2) = 88


12x - 24 - 2y + 4 = 88


12x - 2y = 108


6x - y = 54

The equation above is the simplified first equation.

Second equation:


(2(x + 2))/(5) - (y)/(3) = 6


15 * (2(x + 2))/(5) - 15 * (y)/(3) = 15 * 6


6(x + 2) - 5y = 90


6x + 12 - 5y = 90


6x - 5y = 78

The equation above is the simplified second equation.

The simplified system of equations is:


6x - y = 54


6x - 5y = 78

The x term of both equations is 6x. If we multiply both sides of the second equation by -1 to get a first term of -6x, then when it is added to 6x, the x terms are eliminated.

Now we rewrite the first simplified equation as it is. Below it, we write the second equation multiplied by -1 on both sides. Then we add the equations.


6x - y = 54


-6x + 5y = -78

Add the equations to get:


4y = -24


y = -6

Now we substitute -6 for y in the first simplified equation and solve for x.


6x - y = 54


6x - (-6) = 54


6x + 6 = 54


6x = 48


x = 8

Solution: x = 8; y = -6

User Maddy D
by
7.7k points