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Evaluate −6x+7y when x=3/4 and y=5/8. Write your answer as a fraction in simplest form.

When x=3/4 and y=5/8, −6x+7y=
.

User Tly
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1 Answer

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For this question, all you have to do is replace the x and y with the number that they represent (turn x into 3/4 and y into 5/8).
So, to rephrase the equation after replacing x and y with their given numbers:
-6(3/4)+7(5/8)=
Multiply the number outside of the parentheses with the number inside the parentheses separately, accordingly to the PEMDAS rule:
(-6×3/4)+(7×5/8)
(-18/4)+(35/8)
Now, make sure that both fractions are at the LCD. Since we can’t simplify 35/8, turn -18/4 into -36/8. From there, you can solve the problem.
(-36/8)+(35/8)
OR
(35/8)–(36/8)

The answer, in this case, is **(-1/8).**
User Arancha
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