Xiaoli and several children go to a fast food restaurant for dinner. They bought 10 hamburgers and 10 French fries with 6 yuan money, and spent a total of () in 84 yuan.
Solution: Buy X hamburgers and buy (10-x) French fries.
10x+6( 10-x)=84
10x+60-6x=84
10x-6x=84 -60
4x=24
x=6
I bought six hamburgers.