Question
Solve the system using elimination.
5x + 8y = –29
7x – 2y = –67
(–1, –3)
(–9, 2)
(–7, 9)
Answers
Answered by
GPT 3.5
To solve the system using elimination, we need to eliminate one variable by manipulating the equations.
First, let's multiply the first equation by 2 and the second equation by 8 to make the coefficients of y the same:
2(5x + 8y) = 2(-29)
8(7x - 2y) = 8(-67)
Simplifying, we get:
10x + 16y = -58
56x - 16y = -536
Now we can add the two equations:
(10x + 16y) + (56x - 16y) = -58 + (-536)
Simplifying, we get:
66x = -594
Dividing both sides by 66:
x = -9
Now we can substitute this value of x back into one of the original equations. Let's use the first equation:
5x + 8y = -29
5(-9) + 8y = -29
-45 + 8y = -29
Adding 45 to both sides:
8y = 16
Dividing both sides by 8:
y = 2
Therefore, the solution to the system of equations is (-9, 2).
First, let's multiply the first equation by 2 and the second equation by 8 to make the coefficients of y the same:
2(5x + 8y) = 2(-29)
8(7x - 2y) = 8(-67)
Simplifying, we get:
10x + 16y = -58
56x - 16y = -536
Now we can add the two equations:
(10x + 16y) + (56x - 16y) = -58 + (-536)
Simplifying, we get:
66x = -594
Dividing both sides by 66:
x = -9
Now we can substitute this value of x back into one of the original equations. Let's use the first equation:
5x + 8y = -29
5(-9) + 8y = -29
-45 + 8y = -29
Adding 45 to both sides:
8y = 16
Dividing both sides by 8:
y = 2
Therefore, the solution to the system of equations is (-9, 2).