Answer:
935 = 6a + 3.5c (this is the amount that has been raised)
210 = a + c (this is this amount of the dinners being sold)
Explanation:
so a = 210 - c
935 = (6 * (210 - c)) + 3.5c
6 * 210 is 1260, so:
935 = 1260 - 6c + 3.5c
2.5c = 1260 - 935
2.5c = 325
so c = 130
a = 210 - 130 = 80
We know that 80 adult dinners were sold.
We also know 130 child dinners were sold as well.