Question

HELP PLEASE!!!!!!!!!! Solve -9x+8y=-9 -10x+8y=-2

Answer 1

Answer:

x = -7 , y = -9

Step-by-step explanation:

Solve the following system:

{8 y - 9 x = -9

8 y - 10 x = -2

Hint: | Choose an equation and a variable to solve for.

In the first equation, look to solve for x:

{8 y - 9 x = -9

8 y - 10 x = -2

Hint: | Isolate terms with x to the left hand side.

Subtract 8 y from both sides:

{-9 x = -8 y - 9

8 y - 10 x = -2

Hint: | Solve for x.

Divide both sides by -9:

{x = (8 y)/9 + 1

8 y - 10 x = -2

Hint: | Perform a substitution.

Substitute x = (8 y)/9 + 1 into the second equation:

{x = (8 y)/9 + 1

8 y - 10 ((8 y)/9 + 1) = -2

Hint: | Expand the left hand side of the equation 8 y - 10 ((8 y)/9 + 1) = -2.

8 y - 10 ((8 y)/9 + 1) = 8 y + (-(80 y)/9 - 10) = -(8 y)/9 - 10:

{x = (8 y)/9 + 1

-(8 y)/9 - 10 = -2

Hint: | Choose an equation and a variable to solve for.

In the second equation, look to solve for y:

{x = (8 y)/9 + 1

-(8 y)/9 - 10 = -2

Hint: | Isolate terms with y to the left hand side.

Add 10 to both sides:

{x = (8 y)/9 + 1

-(8 y)/9 = 8

Hint: | Solve for y.

Multiply both sides by -9/8:

{x = (8 y)/9 + 1

y = -9

Hint: | Perform a back substitution.

Substitute y = -9 into the first equation:

Answer: {x = -7 , y = -9