What number, when added to the numerator and to the denominator of 5/8 , results in a fraction whose value is 0.4?
+37170 -3 added to numerator 2
-3 added to denominator 5
2/5 = .4
(5+x) / (8+x) = 4/10
5+x = (8+x) (4/10)
5 + x = 32/10 + 4/10x
1.8 = -6/10 x
1.8 (-10/6) = x
-18/6 = x
x = -3
+37170 -3 added to numerator 2
-3 added to denominator 5
2/5 = .4
(5+x) / (8+x) = 4/10
5+x = (8+x) (4/10)
5 + x = 32/10 + 4/10x
1.8 = -6/10 x
1.8 (-10/6) = x
-18/6 = x
x = -3
