1. If a - b = 4 and a + b = 12, what is the value of a?
1 answer:
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Answer:
(1 , 2
)
Step-by-step explanation:
Given the 2 equations
7x - y = 7 → (1)
x + 2y = 6 → (2)
Multiplying (1) by 2 and adding to (2) will eliminate the y- term
14x - 2y = 14 → (3)
Add (2) and (3) term by term to eliminate y
15x = 20 ( divide both sides by 15 )
x = =
= 1
Substitute this value of x into either of the 2 equations and solve for y
Substituting in (2)
+ 2y = 6
2y = 6 - =
( divide both sides by 2 )
y = = 2