Answer:
7(3^2) + 2(3).
That equals to 7(9) + 2(3).
That equals to 63 + 6.
That finally equals to 69.
Step-by-step explanation:
7h + 6b = 35.50
5h + 6b = 30.50
The difference between the 2 totals spent is $5, and there were the same number of burgers, but 2 fewer hotdogs. So $5/2 = $2.50, the cost of a hot dog. Substitute that into the equations to solve for burgers (b)
5(2.50) + 6b = 30.50
12.50 + 6b = 30.50
6b = 18
b = 3
Check the work:
7(2.50) + 6(3) =
17.50 + 18 = 35.50
She has 6 left.
70%= 0.7
0.7 x 20 = how many she has sold (14)
OR
30%=0.3
0.3 x 20= how many she hasn't sold (6)