Practice Constant vs Variable in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

Constants are symbols with fixed, unchanging values; variables are symbols whose values can change or are yet to be determined.

ฯ€โ‰ˆ3.14159\pi \approx 3.14159 is always the same (constant). xx can be anything (variable).

Showing a random 20 of 50 problems.

Example 1

challenge
In the equation ax+b=0ax + b = 0 with aโ‰ 0a \ne 0 constant and bb constant, give a formula for the variable xx.

Example 2

medium
In y=mx+by = mx + b, which symbols are parameters once a specific line is chosen?

Example 3

easy
In 9โˆ’2x9 - 2x, list the constants.

Example 4

medium
In A=ฯ€r2A=\pi r^2, classify each symbol.

Example 5

challenge
In y=asinโก(bx+c)+dy = a\sin(bx + c) + d, classify each symbol if you study one specific sine curve.

Example 6

easy
In y=7y=7, can yy vary?

Example 7

medium
In P=4sP=4s for a square, classify PP, ss, and 4.

Example 8

easy
Is the speed of light cc a constant or variable in physics?

Example 9

challenge
In f(x)=cf(x) = c for an unknown constant cc, what is the rate of change of ff, and what is f(100)โˆ’f(7)f(100) - f(7)?

Example 10

easy
In 7yโˆ’47y - 4, identify the variable.

Example 11

easy
In 3x+53x+5, name the constants.

Example 12

easy
In 2r2r, if rr is a length that can change, what is rr?

Example 13

medium
In a chemistry formula PV=nRTPV = nRT, identify the constant.

Example 14

easy
In C=2ฯ€rC = 2\pi r, identify the constants and variables.

Example 15

easy
In V=lwhV = lwh, classify each symbol if a box's dimensions can change.

Example 16

challenge
In y=ax+by=ax+b, explain why aa and bb are constants for one line yet behave like variables across the family of all lines.

Example 17

hard
Given y=kxy = kx with kk a fixed proportionality constant. If (x,y)=(4,12)(x, y) = (4, 12) lies on this graph, find kk and then yy when x=9x = 9.

Example 18

medium
A letter cc is a constant in E=mc2E=mc^2 but a variable in y=cxy=cx. Explain in one line.

Example 19

easy
Is ฯ€\pi a constant or a variable?

Example 20

medium
In h(x)=3h(x) = 3, what is the rate of change of the output?