SOLUTION: -19 3/8 - (-4 3/4) I always get confused when there is more than one negative. I don't know if I'm supposed to add or subtract after making into unlike fraction then giving a c

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: -19 3/8 - (-4 3/4) I always get confused when there is more than one negative. I don't know if I'm supposed to add or subtract after making into unlike fraction then giving a c      Log On


   

Question 939189: -19 3/8 - (-4 3/4)
I always get confused when there is more than one negative. I don't know if I'm supposed to add or subtract after making into unlike fraction then giving a common denominator. Help please
Found 3 solutions by ewatrrr, MathLover1, lwsshak3:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
-19 3/8 - (-4 3/4) = -19 3/8 + 4 3/4 (the 2 negatives make it positive)

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
-19+%283%2F8%29-%28-4+%283%2F4%29%29...first write mixed numbers as improprer fractions; multiply the bottom number of the fraction (denominator) times the whole number and then add the top number of the fraction (numerator), then put the answer over the denominator
-%2819%2A8%2B3%29%2F8-%28-%284%2A4%2B3%29%2F4%29%29
-155%2F8-%28-19%2F4%29...since you have minus in front of parentheses and minus inside parentheses, means you are multiplying minus by minus and that will give you plus
so, you will have

-155%2F8%2B19%2F4 ....now write 19%2F4 as %2819%2A2%29%2F%284%2A2%29=38%2F8 to have same denominators

-155%2F8%2B38%2F8

%28-155%2B38%29%2F8 ...here you just subtract 38 from 155 and put negative sign in front of their difference

-117%2F8


Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
-19 3/8 - (-4 3/4)
I always get confused when there is more than one negative. I don't know if I'm supposed to add or subtract after making into unlike fraction then giving a common denominator.
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Here are some of the rules that might help.
1.Clearing parenthesis:
If there is a positive sign or no sign in front, just remove the parenthesis.
If there is a negative sign in front, reverse the sign of items inside the parenthesis then remove the parenthesis.
..
2.Adding terms with the same sign:
If they are all positive, the sum takes a positive sign.
If they are all negative, the sum takes a negative sign.
..
3. Adding terms with unlike signs:
subtract the smaller number from the bigger number and assign the sign of the bigger number to the difference.
..
4.Algebriac subtraction:
Change the sign of the subtrahend(bottom term), then perform addition in accordance with the 3 rules above.
..
Perhaps your math teacher could explain the rules of algebra more elegantly, as I am not a certified teacher. Anyway, I hope this helps.