SAT Math: Interpreting the Context of a Constant
38+ practice questions in Praczo
The concept, explained
- 1
An equation modeling a real-world scenario often contains constants (fixed numbers). The SAT asks what they represent.
- 2
In y = mx + b, "b" is the y-intercept, usually representing an initial starting value, flat fee, or base amount.
- 3
In exponential models y = a(b)^x, "a" is the initial amount and "b" is the growth/decay factor.
- 4
Always look at the units of the variables to determine the units of the constant. If y is total cost in dollars, a constant added to it must also be in dollars.
- ✗ Confusing the initial value (the constant) with a rate of change (the coefficient/slope).
- ✗ Ignoring the units and selecting a description that makes logical sense but differs from the equation's defined variables.
SAT-style practice
The total weight W, in ounces, of a box containing n identical coins is given by W = 0.2n + 5. What does the number 5 represent?
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