Question

7/10+5/8+7/20= and how

Answer 1

67/40

Answer 2

the least common den. is 40
\[\frac{ 7 }{ 10 }*\frac{ 4 }{ 4 }+\frac{ 5 }{ 8 }*\frac{ 5 }{ 5 }+\frac{ 7 }{ 20 }*\frac{ 2 }{ 2 }\]
\[\frac{ 28 }{ 40 }+\frac{ 25 }{ 40 }+\frac{ 14 }{ 40 }\]
\[\frac{ 28 + 25+14 }{ 40 }=\frac{67}{40}\]

Answer 3

How do you get a proper fraction from there?

Answer 4

writing the multiples of 10,8 and 20
10=10 20 30 (40) 50 60
it takes four(4) of the tens to get 40
8=8 16 24 32 (40) 48
it takes five(5) 0f the eights to get 40
20=20 (40) 60 80
it takes two(2) of the twenty to get 40
comparing all the three lowest common multiple(l.c.m) is 40 which is common in all
the original equation is;
7/10+5/8+7/20
since the l.c.m =40
we divide through by 40
((7*4)+(5*5)+(7*2)) /40
this gives
(28+25+14)/40
the final answer is
67/40