This can be explained in another way. when you have a/b=c/d, you get ad=bc. In this problem, 3/(5x+1) = 2/9, therefore, 9x3 = 2(5x+1) 27=10x+2 Move 2 to the other side, by changing the sign, 27-2 = 10x, 25=10x, x = 25/10 = 2.5

mathsyperson

2005-07-11 04:36:25

3/(5x+1)=2/9 Multiply by (5x+1): 3=2(5x+1)/9 Multiply by 9: 27=2(5x+1) Multiply out of brackets: 27=10x+2 Take away 2: 25=10x Divide by 10: x=2.5