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19 votes
7x - 5y = -24
-9x + 5y = 18

User Povilasp
by
2.9k points

2 Answers

11 votes

Answer:

Assuming this is a system of equations...

Point form > (3, 9)

Equation form > x = 3, y = 9

Explanation:

So we need to solve for x in 7x - 5y = -24

Add 5y to both sides

7x = -24 + 5y

-9x + 5y = 18

Divide each term by 7

7x/7 = -24/7 + 4y/7

-9x + 5y = 18

x = -24/7 + 5y/7

-9x + 5y = 18

Now we need to replace all occurences of x with -24/7 + 5y/7

-9(-24/7 + 5y/7) + 5y = 18

x = -24/7 + 5y/7

So lets focus on simplifying -9(-24/7 + 5y/7) + 5y

Apply the distributive property

-9(-24/7) - 9 5y/7 + 5y = 18

Now multiply -9(-24/7)

So -1 by -9

9(24/7) - 9 5y/7 + 5y = 18

Combine 9 and 24/7

9 * 24/7 - 9 5y/7 + 5y = 18

Then Multiply 9 by 24

216/7 - 9 5y/7 + 5y = 18

Now we multiply -9 5y/7

So Combine -9 and 5y/7

216/7 + -9(5y)/7 + 5y = 18

Now Multiply 5 by -9

216/7 + -45y/7 + 5y = 18

Move the negative

216/7 - 45y/7 + 5y = 18

Now we need to multiply by 7/7 to make 5y a fraction with a common denom.

216/7 - 45y/7 + 5y * 7/7 = 18

Combine

216/7 + -45y + 5y * 7/7 = 18

Combine further

216 - 45y + 5y * 7/7 = 18

Multiply

216 - 45y + 35y

Add

216 - 10y/7 = 18

Factor 2 out of the equation

2(108) - 10y/7 = 18

Factor more

2(108) + 2(-5y)/7 = 18

Factor further

2(108 - 5y)/7 = 18

Now we want to solve for y in 2(108 - 5y)/7 = 18

Multiply both sides by 7 then simplify.

2(108 - 5y) * 7/7 = 18 * 7

2 * 108 + 2 (-5y) = 18 * 7

Multiply

216 + 2 (-5y) = 18 * 7

Multiply again

216 - 10y = 18 * 7

Reorder 216 and -10y

-10y + 216 = 18 * 7

Simplify the right side

-10y + 216 = 126

Now we need to solve for y

So lets move all terms not containing y to the right side.

-10y = 126 - 216 (Subtract 216 from both sides)

-10y = -90

Divide each term by -10

-10y/-10 = -90/-10

Simplify the left side

-90/10

And the right side

y = 9

x = -24/7 + 5y/7

Now replace y with 9

-24/7 + 5(9)/7

Simplify the right side

-24 + 5(9)/7

Multiply

-24 + 45

Add

21/7

x = 3

Therefore x = 3, y = 9 > (3, 9)

User Alexey Petushkov
by
3.6k points
9 votes

Answer:

Nothing further can be done with this topic. Please check the expression entered or try another topic.

7x−5y=−24−9x+5y=187x-5y=-24-9x+5y=18