Practice Variable as Generalization in Math

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

Quick Recap

A variable standing for any arbitrary member of a specified set, used to express statements that hold universally.

'For any number nn, n+0=nn + 0 = n' works for ALL numbers, not just one.

Showing a random 20 of 50 problems.

Example 1

medium
Generalize: the area of a triangle with base bb and height hh is what?

Example 2

hard
Write a general formula for the nnth term of 3,7,11,15,โ€ฆ3, 7, 11, 15, \dots.

Example 3

medium
Classify: '(aโˆ’b)(a+b)=a2โˆ’b2(a - b)(a + b) = a^2 - b^2' โ€” identity or conditional equation?

Example 4

challenge
Prove or disprove: 'For every integer nn, n2โˆ’nn^2 - n is even.' Give a general argument.

Example 5

medium
A pattern: 1=121=1^2, 1+3=221+3=2^2, 1+3+5=321+3+5=3^2. Generalize the sum of the first nn odd numbers.

Example 6

challenge
Prove that the product of two consecutive integers is even.

Example 7

medium
Explain why (n+1)2โˆ’n2=2n+1(n+1)^2 - n^2 = 2n + 1 is true for every integer nn.

Example 8

medium
Is 'n+n+n+n=4nn+n+n+n=4n' a generalization that holds for all nn? Justify.

Example 9

medium
Write a general formula for the sum of the first nn even positive integers.

Example 10

medium
Is 2n+12n + 1 odd for every integer nn? Justify.

Example 11

easy
Does n+0=nn + 0 = n hold for every number nn?

Example 12

medium
Is 'aa=1\frac{a}{a}=1' true for every number aa? Explain the exception.

Example 13

medium
Identify the domain: '1x\frac{1}{x} is defined for every ____.'

Example 14

easy
Is '2+3=52 + 3 = 5' a generalization or a single arithmetic fact?

Example 15

hard
Find a counterexample to 'x2>xx^2 > x for every real xx'.

Example 16

medium
Is the equation โˆฃxโˆฃ=x|x| = x true for every real xx?

Example 17

medium
Write a general formula for the sum of the first nn positive integers.

Example 18

hard
Prove the sum of two consecutive integers is always odd.

Example 19

hard
Is 'aa=1\frac{a}{a} = 1' true for every real aa? If not, restrict the domain.

Example 20

medium
Generalize: the perimeter of a square with side ss is what?