Question 481239: Solve and graph solution set that is not empty.
-2y < -8 or 1 + 2y <3
My answer is y>-4 or y<1 is it correct?
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! -2y < -8
or:
1 + 2y < 3
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-2y < -8 becomes y > 4
you divide both sides of the equation by -2 to get:
y > 4
the division by a negative number changes the inequality sign.
-8 / -2 = +4
if y = 4 which is equal to 4, -2y = -8 which is equal to -8.
if y = 5 which is greater than 4, -2y = -10 which is less than -8
if y = 3 which is less than 4, 3, -2y = -6 which is greater than -8
this means -2y < -8 is true when y > 4 and false when y = 4 and when y < 4.
answer is -2y < -8 when y > 4.
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1 + 2y < 3 becomes 2y < 2 becomes y < 1
if y = 1 which is equal to 1, 1 + 2y = 3 which is equal to 3.
if y = 2 which is greater than 1, 1 + 2y = 1 + 4 = 5 which is greater than 3.
if y = 0 which is smaller than 1, 1 + 2y = 1 which is less than 3.
this means that 1 + 2y < 3 is true when y is less than 1 and false when y = 1 and when y > 1.
answer is 1 + 2y < 3 when y < 1.
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answer that satisfies both equations is:
y > 4 or y < 1.
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you had y > -4
check you answer out again.
you looked ok with y < 1
that y > -4 is suspect.
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