75% of what is 0.90
0.75x = 0.90
x = 0.90/0.75
x = 1.20 <== restaurant pays $ 1.20 wholesale
You are correct! You added the two amounts together. Combined the like terms, 7t +8t=15t and -1+5=4
To find the angle use arc tan (-5/-7) which simplifies tips arctan(5/7). arc tan is tan to the power -1, which is also called inverse tan. The heading of the angle, if you drew this out on a graph your angle would be in the third quadrant and therefore the heading is south of west.
