Inactive Tutor answered • 01/09/13
Hi Kaitlin, First we need to make the problem clear. A good way is to use parentheses ( ) to group terms. So is your problem: (2 1/2)(x) - (2 1/4) = (3 2/5) ?
Assuming that is what you mean, get all the terms that do NOT have x all together on one side of the =, and leave only the term with x on the other side. We do that by adding/subtracting the terms we don't want from both sides of the equation ("whatever you do to one side, you must also do to the other, to keep it equal")
(2 1/2)(x) - (2 1/4) + (2 1/4) = (3 2/5) + (2 1/4)
(2 1/2)(x) = (3 2/5) + (2 1/4) = 113/20 (changed 3 2/5 to 17/5, and 2 1/4 to 9/4, then used a common denominator of 5*4 = 20, so 17/5 = 68/20, and 9/4 = 45/20: 68/20 _ 45/20 = 113/20)
For the x-term on the left, let's make it a simple fraction: 1 1/2 = 5/2, and (5/2)(x) = 5x/2
Now we have 5x/2 = 113/20
Multiply both sides of the = by 2 to get 5x alone: (5x/2)(2) = (113/20)(2)
5x = 226/20
Now divide both sides by 5 to get x alone: 5x/5 = (226/20) / 5
x = 226/100, or x = 2.26, or x = 2 26/100, or x = 2 13/50
