Answer: choice A) [tex]7d^2[/tex]
This is the same as writing 7d^2
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Explanation:
When we add a number to itself repeatedly, we can use multiplication to shorten things. For example: 3+3+3+3 = 5*3 = 15. We have five copies of '3' being added, which explains the 5 times 3.
Extending this idea leads us to shortening repeated multiplications into exponentiations. In the case of [tex]7*d*d[/tex], we have two copies of 'd' being multiplied. We replace [tex]d*d[/tex] with [tex]d^2[/tex] which is the same as d^2. The ^ symbol means "exponent".
The exponent (2) tells us how many copies of the base (the term d) we multiply out.
Another example would be [tex]d^3 = d*d*d[/tex]
So that's why [tex]7*d*d = 7d^2[/tex]
