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 n, n+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 b and height h is what?

Example 2

hard
Write a general formula for the nth term of 3,7,11,15,….

Example 3

medium
Classify: '(a−b)(a+b)=a2−b2' — identity or conditional equation?

Example 4

challenge
Prove or disprove: 'For every integer n, n2−n is even.' Give a general argument.

Example 5

medium
A pattern: 1=12, 1+3=22, 1+3+5=32. Generalize the sum of the first n odd numbers.

Example 6

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

Example 7

medium
Explain why (n+1)2−n2=2n+1 is true for every integer n.

Example 8

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

Example 9

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

Example 10

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

Example 11

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

Example 12

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

Example 13

medium
Identify the domain: '1x is defined for every ____.'

Example 14

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

Example 15

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

Example 16

medium
Is the equation ∣x∣=x true for every real x?

Example 17

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

Example 18

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

Example 19

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

Example 20

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