# solve for x, includes fractions of x and exponents

• Apr 16th 2010, 10:18 AM
capriblonde
solve for x, includes fractions of x and exponents
Solve for x:

[x/1.06]+[0.8x/1.06^2]+[0.64x/1.06^3]=28370

I know the final answer should be x=12940 but can anyone explain step by step how to get there please?

Thanks
Hannah
• Apr 16th 2010, 10:22 AM
wonderboy1953
First step
Multiply both sides of the equation by \$\displaystyle 1.06^3\$
• Apr 17th 2010, 04:33 AM
CausingTraumaZ
Quote:

Originally Posted by capriblonde
Solve for x:

[x/1.06]+[0.8x/1.06^2]+[0.64x/1.06^3]=28370

I know the final answer should be x=12940 but can anyone explain step by step how to get there please?

Thanks
Hannah

As wonderboy1953 said multiply both sides by 1.06^3 then simplify the expressions..
Then you have 1.06²x+1.06*0.8x+0.64x=33789.12392
you can write 1.06 as 53/50
so we get:

(53/50)²x+212x/250+16x/25=33789.12392

2809x/2500+212/250x+16x/25=33789.12392

(2809x+2120x+1600x)/2500=33789.12392

6529x/2500=33789.12392

x=33789.12392*2500/6529

x=12940

Hope this helped!