Answer: 20: 10x + 20y = P
21: f(x) = -2y + 10
y can be 0 or even numbers from 2 to 10
Step-by-step explanation: 20:
The number of shirts times 10 is the price of the shirts. That is 10x in the equation.
The number of shorts times 20 is the cost of the shorts. That is 20 y in the equation. The total price, P, is the sum of 10x + 20y.
21: 10x + 20y = 100 This is the basic situation in standard form. Shirts and shorts add to 100
10x + 20y - 100 = 0 starting point to create the equation as number of shirts as a function of number of shorts. NOTE: this opposite of normal. Usually the y-value is the output.
10x = -20y + 100 . simplify
x = -2y + 10 This defines the number of shirts Jackson can buy based on the number of shorts.
The attached graph of the solution consists of 6 coordinates.
It is impossible to buy partial shorts or partial shirts. So, for example, if he buys 4 shorts, he can buy 2 shirts. If he buys no shorts, he can buy 10 shirts. Or if he buys 5 shorts he can buy no shirts. The question states that he must spend $100.
