Answer:
The number of friends that went out for dinner is 8
And their bill is $238
Step-by-step explanation:
Let's assume that the number of friends that went out for dinner to be x
And the bill for the dinner to be y
If each person contributed $32 and paid off the bill,they will have a balance of $18
32x - 18 = y_____equation 1
If each person contributed $35 and paid off the bill and also 15% tip,they will have a balance of $6.30
35x - 6.3 = y + (15% of y)
35x - 6.3 = y + (3y/20)
Open up the bracket
35x - 6.3 =(20y + 3y)/20
700x - 126 = 23y______equation 2
From equation 1,y = 32x - 18
Put the above in equation 2 and we have
700x - 126 = 23(32x -18)
700x - 126 = 736x - 414
collect like terms
36x = 288
x = 288/36
x = 8
Remember that equation 1 says that y = 32x - 18 and we now know that x = 8 .
Substitute and we have
(32 × 8) - 18
y = 238
The number of friends that went out for dinner is 8
And their bill is $238
Gotta graph this one
Zeros are $.586 and $3.414 and the profit is zero when these are the prices
Maximum profit when the dogs are 2 bucks
7 will never equal 8 so there is no solution. so i think it is C
