SOLUTION: pre-algebra operations with positive and negative fractions. multiply. -3/4x2/5-1/8. in working the problem i did the multiplication first. -3/4x2/5 to get -3/2x1/5 then -3times1

Question 125734This question is from textbook pre-algebra DeMystified
: pre-algebra operations with positive and negative fractions. multiply. -3/4x2/5-1/8. in working the problem i did the multiplication first. -3/4x2/5 to get -3/2x1/5 then -3times1=-3 then two times five = 10 for an answer of -3/10-1/8=3/80. wrong answer. the book states -17/40 as the answer. I worked the problem again and got 7/40. this is as close as i can get to -17/40. why is this a negative number and how is the answer 17/40 and not 7/40? please help !!! thanks stumped..... This question is from textbook pre-algebra DeMystified

Answer by applesrbest(7) (Show Source): You can put this solution on YOUR website!
The first part of your working is correct, until -3/10-1/8.
-3/10-1/8
= -12/40-5/40 (both numerator & denominator is multiplied by 4 for -3/10 and 5 for -1/8)
= -17/40 (there is still a minus sign in front of 12/40 so another way to see it is 0-12/40-5/40=-17/40 and not just 12/40-5/40=7/40)
=) hope this answers your query.
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