2x+( 1 1-x)= 18。
solve
x=7
1 1-x=4
So this class won seven games and lost four.
2( 1), original price eggs per 14/30 yuan.
After buying two boxes of special eggs, Li Ming actually consumed 30*2-20=40 eggs. According to this calculation, each egg uses12 * 2/40 = 3/5 =18/30 yuan, which is more expensive than the original eggs, so it is not cost-effective for Li Ming to buy two boxes of eggs.
(2) Suppose Zhang Xin bought X boxes of special eggs, 12x= 14x*2-96.
Solution: x=6
So Zhang Xin bought six boxes of discounted eggs. six
A box contains 30 * * * 6 = 180 eggs, so the average daily consumption of eggs in Zhang Xin store is 180/ 18= 10, which will not be wasted.
3( 1). Obviously, Lili is more than 3 kilometers away from her grandmother's house. She walked 3km with 8 yuan, and then walked (17.6-8)/ 1.6 = 6km, so the distance from Lili's house to her grandmother's house is 3+6 = 9km.
(2) If Miss Wang uses one-way billing, it needs *2=25.6 yuan, and if she uses one-time billing, it needs 8+(3+6)* 1.2= 18.8 yuan, so it is more economical to use one-time billing.