fraction problem 7:
Determine the lowest common denominator and calculate the value, reduce the solution and write as a mixed fractions if possible!
7 11/12 – 4 3/5 – 1 2/3 =
answer:
transform in improper fractions:
7 11/12 = 7 * 12 + 11 = 95/12
4 3/5 = 4 * 5 + 3 = 23/5
1 2/3 = 1 * 3 + 2 = 5/3
→ 95/12 – 23/5 – 5/3 =
the lowest common denominator:
12 = 2 * 2 * 3
5 = 1 * 5
3 = 1 * 3
2 * 2 * 3 * 5 = 60
calculate the value:
to make the bottom numbers the same you have to multiply the top and the bottom of
the first fraction with 5 (because 12 * 5 = 60)
the second fraction with 12 (because 5 * 12 = 60)
the third fraction with 20 (because 3 * 20 = 60)
95/12 – 23/5 – 5/3 =
95*5/12*5 – 23*12/5*12 – 5*20/3*20 =
475/60 – 276/60 – 100/60 =
475/60 – 376/60 = 99/60
simplify the value by 3:
99:3/60:3 = 33/20
write as a mixed fraction:
33/20 = 1 13/20 (33 : 20 = 1 and 13/20)