What is the solution to this system of equations using elimination. -7x -8y =9 and -4x + 9y = -22

x = 1

y = -2

Step-by-step explanation:

We have the system of equations:

-7*x - 8*y = 9

-4*x + 9*y = -22

To solve this type of system, we need to start by isolating one of the variables in one of the equations.

I will isolate the variable x in the first equation to get:

-7*x - 8*y = 9

-7*x = 9 + 8*y

x = (9 + 8*y)/(-7)

x = -(9 + 8*y)/7

Now we can replace this in the other equation to get:

-4*(-(9 + 8*y)/7) + 9*y = -22

And now we can solve this for y, we will get:

(4/7)*(9 + 8*y) + 9*y = -22

(4/7)*9 + y*(9 + 8*(4/7)) = -22

y*(63/7 + 32/7) = -22 - (36/7)

y*(95/7) = -(22*7/7) - (36/7)

y = (7/95)*(-(22*7/7) - (36/7)) = (-22*7 - 36)/95 = -2

y = - 2

Now we can replace this in the equation x = (9 + 8*y)/(-7) to find the value of x:

x = (9 +8*(-2))/(-7) = 1

Then the solution for the system is the pair (1, -2)

That means:

x = 1

y = -2

Step-by-step explanation:

we have

Convert mixed number to an improper fraction

so

Convert percent number as a fraction

Simplify

Divide by 5 both numerator and denominator