9514 1404 393
Answer:
2a. (x, y) = (2, 2)
2b. (x, y) = (3, -1)
3. -5, 3, y, 5, 1
Step-by-step explanation:
2A.
The first equation defines an expression for x, so it is convenient to use that to substitute for x in the second equation.
2(3y-4) -y = 2 . . . . . substitute for x
6y -8 -y = 2 . . . . . . eliminate parentheses
5y = 10 . . . . . . . . . add 8, collect terms
y = 2 . . . . . . . . . . divide by 5
x = 3(2) -4 = 2 . . . find x using the first equation
The solution is (x, y) = (2, 2).
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2B.
Add 3 times the second equation to the first.
(3x +2y) +3(-x +y) = (7) +3(-4)
5y = -5 . . . . . simplify
y = -1 . . . . . . . divide by 5
x = y +4 = -1 +4 = 3 . . . . rearrange the second equation
The solution is (x, y) = (3, -1).
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3.
The slope of this equation is -5 [the x-coefficient]. I would start at +3 [the y-intercept] on the y axis and then drop down 5 and run over 1 .
[The slope is the ratio of rise to run. A slope of -5 means the "rise" is a drop of 5 for each "run" of 1 unit to the right.]
