the easiest way to do do this is to first find out how much % 500 is of 700
first, we can just set it up as a simplified fraction
![(7)/(5)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/zca9xc47x6ldp104rtaye6ks2094ytchj2.png)
which is equal to..
![1.4](https://img.qammunity.org/2019/formulas/mathematics/high-school/t24mrv9xgbk3aazjkfhvgkklpdt574oy35.png)
then we divide 100 by this number
![100 / 1.4 = 71.4285...](https://img.qammunity.org/2019/formulas/mathematics/high-school/mlwspb9anbybn9gauna5xjil5fu5aw2nxn.png)
*now to check*
multiply the quotient by .01 to get .7142...
then multiply that by 700
we should get a product of 500, confirming our answer
now that we're sure, subtract 71 from 100 to find the percentage decrease
![amswer = 29\%](https://img.qammunity.org/2019/formulas/mathematics/high-school/gbw1gl50dbbmnvtj0epfsl9funxs7org3t.png)