18/42=3/7
45/65=9/ 13
So 45/65 is very big.
There is a pile of chemical fertilizer, 3 tons used, and 12 tons left. How much is this pile of fertilizer used?
3÷( 12+3)= 1/5
The simplest fraction converted from a fraction is 5/8, and the denominator of the original fraction is 30 larger than the numerator. What is the numerator of the original fraction?
Let the denominator x be X-30.
(x-30)÷x=5/8
8x-240=5x
3x=240
x=80
80-30=50
The original partial molecule 50