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5 votes
-5x+6y=33
-18x+4y=-22

User Sarmahdi
by
5.0k points

1 Answer

5 votes

Answer:

The correct answer is x = 3 and y = 8

Explanation:

1. First equation

- 5x + 6y = 33

-5x = 33 - 6y

- x = 33/5 - 6y/5 (Dividing by 5 at both sides of the equation)

x = - 33/5 + 6y/5 (Multiplying by - 1 at both sides of the equation)

2. Second equation

- 18x + 4y = -22

- 18 (-33/5 + 6y/5) + 4y = - 22 (Replacing x by the result of the 1st equation)

594/5 - 108y/5 + 4y = - 22

594 - 108y + 20y = -110 (Multiplying by 5 at both sides of the equation)

-88y = -110 - 594

-88y = -704

-y = - 8 (Dividing by 88 at both sides of the equation)

y = 8 (Multiplying by - 1 at both sides of the equation)

3. Replacing y in the first equation for finding x

x = - 33/5 + 6(8)/5

x = - 33/5 + 48/5

x = 15/5

x = 3

4. Proof of x =3 and y = 8

-5x + 6y = 33

-5 (3) + 6 (8) = 33

-15 + 48 = 33

33 = 33

It's proved that x = 3 and y= 8 are correct

User Marcelo Paco
by
5.3k points