algebra week 4 2

Question

Solve the following equation for x:

2x/3 - 4x/5 = 1/15

please show steps

Answer 1

2x/3 - 4x/5 = 1/15

1st step: find common denom for left side: 3 x 5 = 15

2nd step: apply CD to each fraction on left side. 3 into 15 = 5; 5 x 2x = 10x. New fraction 10x/15

5 into 15 is 3; 3 x -4x = -12x. New fraction is -12x/15

Equation is now10x/15 - 12x/15 = 1/15. Since both denoms are 15, can ignore, or just mult both sides of equation by 15 to eliminate.

10x - 12x = 1 -> -2x = 1 -> x = -1/2. You can check by substituting back into original eqn (always a good idea!). Will provide more fraction practice!

Answer 2

The first step is to get rid of the fractions by multiplying by the LCD, in this case it is 15.

15(2/3x)-15(4/5x)-15(1/15) Multiply

5(2x)-3(4x)=1 Multiply

10x-12x=1 Combine like terms

-2x=1 Divide both sides by -2

x=-1/2