To solve the problem we must know about Exponents.
An exponent shows the number of times a number is multiplied by itself. It is represented by a number(or variable) in superscript form.
For example, 3², 4³, etc.
To find
We can write the expression as follows,
1. [tex]8^2 -8=56\\64 - 8 =56\\56 = 56[/tex]
2. [tex]7^2 +7=56\\49+7 =56\\56=56[/tex]
3. [tex]5^2 + 31 =56\\25 +31 =56\\56 =56[/tex]
Learn more about Exponent:
https://brainly.com/question/5497425
