Answer:
-1.5
Step-by-step explanation:
3/4 of -8 is -6
1/4 of -6 is -1.5
if it is not supposed to be -8 the answer is 1.5
9h + 3f = 24.75....multiply by 4
6h + 4f = 19.50 ...multiply by -3
----------------------
36h + 12f = 99 (result of multiplying by 4)
-18h - 12f = - 58.50 (result of multiplying by -3)
--------------------add
18h = 40.50
h = 40.50/18
h = 2.25 <== hamburgers cost 2.25 each
6h + 4f = 19.50
6(2.25) + 4f = 19.50
13.50 + 4f = 19.50
4f = 19.50 - 13.50
4f = 6
f = 6/4
f = 1.50 <== fries cost 1.50 per order
This works because she added the number to she if she got right
1/ 1/5 is about the only other thing I could think of. Hope you do well and good luck.