fractions problem 8:
Determine the lowest common denominator and calculate the value, reduce the solution and write as a mixed fractions if possible!
7/15 + 5/9 – 9/10 =
answer:
the lowest common denominator:
15 = 3 * 5
9 = 3 * 3
10 = 2 * 5
2 * 3 * 3 * 5 = 90
calculate the value:
to make the bottom numbers the same you have to multiply the top and the bottom of
the first fraction with 6 (because 15 * 6 = 90)
the second fraction with 10 (because 9 * 10 = 90)
the third fraction with 9 (because 10 * 9 = 90)
7*6/15*6 + 5*10/9*10 – 9*9/10*9 =
42/90 + 50/90 – 81/90 =
92/90 – 81/90 = 11/90