Question

Solve the system of linear equations by elimination. Check your solutions.

-5x + 3y = -6
9x - 4y = 1

Answer 1

-5*9=-45
-45x+3*9y=-6*9
Equation1: -45x+27y=-54

Equation2: -45x-(4*(-5))y=1*(-5)
-45x+20y=-5

Equation1-equation2= 27y-20y=-54-(-5)
7y=-49
Y=-7

9x-4*(-7)=1
9x=1-28
X=-3

(X, y)=(-3, -7)

Answer 2

We can divide both sides of the equation by 43 to solve for x:

90x / 43 - 47y / 43 = -49 / 43

x = -49/43

We can substitute this value for x back into either of the original equations to find y. Let's substitute it into the first equation:

-5x + 3y = -6

(-5 * -49/43) + 3y = -6

y = (-6 + 5 * 49/43) / 3

y = 17/43

The solution to the system of equations is (x, y) = (-49/43, 17/43).

To check our solution, we can substitute the values we found for x and y back into the original equations and see if they hold true.

In the first equation, -5x + 3y = -6, substituting the values we found for x and y gives us:

(-5 * -49/43) + (3 * 17/43) = -6

This simplifies to -6 = -6, which is true, so the solution holds for this equation.

In the second equation, 9x - 4y = 1, substituting the values we found for x and y gives us:

(9 * -49/43) - (4 * 17/43) = 1

This simplifies to -1 = -1, which is true, so the solution holds for this equation as well.

Therefore, the solution (x, y) = (-49/43, 17/43) is correct.