SOLUTION: Mary has a hamburger stand in town. She says there is a linear relationship between the price (p) of hamburgers and the number sold (x) i.e. 𝒙=𝒂𝒑+𝒃.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Mary has a hamburger stand in town. She says there is a linear relationship between the price (p) of hamburgers and the number sold (x) i.e. 𝒙=𝒂𝒑+𝒃.      Log On


   



Question 1123746: Mary has a hamburger stand in town. She says there is a linear relationship between the price (p) of hamburgers and the number sold (x) i.e. 𝒙=𝒂𝒑+𝒃. At N$10 she sells 1360 hamburgers per month, but only 510 when she doubles the price.
a) Find a and b
(b) How many hamburgers will be sold at N$16?
(c) What price will ensure sales of 1020 hamburgers?
(d) What is the maximum possible price?

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

x=ap%2Bb
x, number sold
p, price

Points might be thought order pairs, (p,x).
The description using that form of equation gives this system:
10a%2Bb=1360....eq.1
20a%2Bb=510.....eq.2
----------------------------------------------
a) Find a and b
Simplify and solve for a and+b.
10a%2Bb=1360....eq.1
20a%2Bb=510.....eq.2
----------------------------------------------subtract eq.1 from rq.2
20a%2Bb+-%2810a%2Bb%29=510-1360
20a%2Bb+-10a-b=510-1360
20a%2Bcross%28b%29+-10a-cross%28b%29=-850
10a=-850
highlight%28a=-85%29
substitute it in eq.1 and find b
10%2A%28-85%29%2Bb=1360....eq.1
-850%2Bb=1360
b=1360%2B850
highlight%28b=2210%29
so, your equation is: x=-85p%2B2210

(b) How many hamburgers will be sold at N$16?
x=-85p%2B2210
x=-85%2A16%2B2210
x=-1360%2B2210
highlight%28x=+850%29

(c) What price will ensure sales of 1020 hamburgers?
x=-85p%2B2210
1020=-85p%2B2210
85p+=2210-1020
85p+=1190
p+=1190%2F85
highlight%28p+=14%29

(d) What is the maximum possible price?
x=-85p%2B2210
find out what price will sell x=0 hamburgers
0=-85p%2B2210+
85p=2210
p=2210%2F85
p=26 -> the maximum possible price
if you want to sell something, the maximum possible price must be less than $26
if we go with $25, we will get
x=-85%2A25%2B2210+
x=-2125%2B2210+
x=85+
the maximum possible price of $25 will result in 85 sold