Praxis Core Academic Skills for Educators: Mathematics (5733)Algebra and FunctionsMedium
A chef is creating a new recipe. The amount of sugar (S) in grams needed for a cake is a function of the amount of flour (F) in grams, given by S(F) = 0.6F - 20. If the chef uses 300 grams of flour, how much sugar is needed?
- A180 grams
- B220 grams
- C200 grams
- D160 grams
Show answer & explanationAnswer & explanation
Correct answer: D. 160 grams
To find the amount of sugar needed, substitute F = 300 into the function S(F) = 0.6F - 20. So, S(300) = 0.6(300) - 20 = 180 - 20 = 160 grams.
Why the other options are wrong
- A. This is 0.6 * 300, forgetting to subtract 20.
- B. Incorrect calculation or misunderstanding of the function.
- C. Incorrect calculation or misunderstanding of the function.
Evaluating Functions
The process of substituting a specific input value into a function's expression to determine its corresponding output value.
- Replace every instance of the independent variable with the given input value.
- Follow the order of operations (PEMDAS/BODMAS) to simplify the expression.
- The result is the function's output for that specific input.
Memory trick: Plug it in, work it out!