Practice Symmetry in Operations in Math

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

Quick Recap

When exchanging or swapping operands or roles in an operation produces the same result or a symmetrically related one.

3+5=5+33 + 5 = 5 + 3 shows addition is symmetric. 3โˆ’5โ‰ 5โˆ’33 - 5 \neq 5 - 3 shows subtraction isn't.

Showing a random 20 of 50 problems.

Example 1

medium
For addition, show that if a+b=ca + b = c, then b+a=cb + a = c (symmetry). Use a=12,b=7a=12, b=7.

Example 2

hard
Is the operation aโ—Šb=aba \Diamond b = a^b symmetric? Justify briefly.

Example 3

medium
Is aโ‹†b=a2+b2a\star b = a^2+b^2 symmetric? Justify.

Example 4

hard
Is the 'less than or equal' relation โ‰ค\le symmetric? If 3โ‰ค53 \le 5, is 5โ‰ค35 \le 3?

Example 5

medium
Is the operation aโ‹†b=ab+1a\star b = ab+1 symmetric? Justify.

Example 6

hard
A vending machine charges \$1 then dispenses a snack. Is the order of 'pay' and 'dispense' symmetric? What's the everyday lesson?

Example 7

easy
Show that for any a,ba, b, a+b=b+aa + b = b + a using a=14,b=9a = 14, b = 9.

Example 8

easy
Does 8โˆ’58 - 5 equal 5โˆ’85 - 8? What does this tell us about subtraction's symmetry?

Example 9

medium
Is f(x)=x+1f(x)=x+1 symmetric as a graph about the yy-axis, even though addition is symmetric?

Example 10

easy
Is 20โˆ’720 - 7 the same as 7โˆ’207 - 20?

Example 11

challenge
For how many ordered pairs of digits (a,b)(a, b) with a,bโˆˆ{1,2,3,4,5}a, b \in \{1,2,3,4,5\} is ab=baa^b = b^a?

Example 12

challenge
Show that aโ‹†b=abโˆ’aโˆ’ba\star b=ab-a-b is symmetric and find a value where aโ‹†b=bโ‹†a=0a\star b=b\star a=0.

Example 13

easy
Is exponentiation symmetric? Compare 232^3 vs 323^2.

Example 14

challenge
A relation โˆผ\sim is symmetric and aโˆผba\sim b holds. If also aโˆผaa\sim a always holds, what two relation properties are present, and is โˆผ\sim necessarily transitive?

Example 15

medium
Is the operation aโ‹†b=โˆฃaโˆ’bโˆฃa\star b=|a-b| symmetric? Test and justify.

Example 16

easy
Is the relation 'less than' (<<) symmetric? If 3<53<5, is 5<35<3?

Example 17

easy
Is the relation 'equals' symmetric? If a=ba=b, does b=ab=a?

Example 18

medium
Is the operation 'average', aโ‹†b=a+b2a\star b=\frac{a+b}{2}, symmetric?

Example 19

medium
Use symmetry of multiplication to compute 25ร—17ร—425 \times 17 \times 4 quickly.

Example 20

easy
Does a+b=b+aa+b=b+a require a=ba=b?