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 Put 3 in there where B is

B+7   would be   3+7 = 10

B^2-10  would be 3^2-10 =-1     10 * -1 = -10

So we know that our given varible is B and that it eqaul's 3, so we substatuite that into our equation 

\((3 +7)({3}^{2}-10)\)

Two thing's we want to remember is PEMDAS and that (3 + 7) and (3² - 10) are to multiply on one another we can tell this because both equations are next to each other to indicate multiplication there closed in parenthasses because there both seperate values and they want you to solve for each value before multiplying. 

So \((3 + 7) = 3 + 7 = 10\)

we end up with a sum of   \((10)\) 

For the second part: \(({3}^{2}-10)\)

We need to remeebr that we need to take care of exponet's first in pemdas, because it is the first one avaible the parenthassis just symbolizes that this is one value. 

So 3²  =  9 and 9 - 10  =  -1 

Our final equation should look like this: \((10)(-1)\)and we know this mean's 10 * -1 and all you have to do is 

1. Multiply the factor's. 

2. Get your product. 

3. Dispaly your product as your answer.