The solution of the system of equations is (-3 , -2)
Step-by-step explanation:
Steps for Using Linear Combinations Method)
- Arrange the equations with like terms in columns
- Analyze the coefficients of x or y
- Add the equations and solve for the remaining variable
- Substitute the value into either equation and solve
∵ 3 x - 8 y = 7 ⇒ (1)
∵ x + 2 y = -7 ⇒ (2)
- Multiply equation (2) by 4 to make the coefficients of y are equal in
magnitude and different in sign
∴ 4 x + 8 y = -28 ⇒ (3)
Add equations (1) and (3)
∵ 3 x - 8 y = 7 ⇒ (1)
∵ 4 x + 8 y = -28 ⇒ (3)
∴ 7 x = -21
- Divide both sides by 7
∴ x = -3
Substitute the value of x in equation (2) to find y
∵ x + 2 y = -7 ⇒ (2)
∵ x = -3
∴ -3 + 2 y = -7
- Add 3 to both sides
∴ 2 y = -4
- Divide both sides by 2
∴ y = -2
The solution of the system of equations is (-3 , -2)
Learn more:
You can learn more about the system of the linear equations in brainly.com/question/13168205
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Answer:
sorry abs
Step-by-step explanation:
If 7 is the value F it makes the equation true!
Old price: p1 = $ 3.90;
New price: p2 = $ 3.40.
The percentual decrease is given by
d(%) = [ (p2 - p1) / p1 ] * 100 %
d(%) = [ (3.40 - 3.90) / 3.90 ] * 100 %
d(%) = [ - 0.50 / 3.90 ] * 100 %
d(%) = - 0.128 * 100 %
d(%) = - 12.8 % (approximately)
So the price fell 12.8 % approximately.
I hope this helps. =)
