D) the answers growth because when the number 7 (in that position) is raised to a power it will grow at the rate of 7 to the power of (x)
If we know that Pedro bought 1

pounds of red sand, and 5

pounds of brown sand, and they both cost $4.60, then we just have to add the individual amounts of sand, since they cost the same.

So Pedro bought

lbs of sand overall. Now, we just need to multiply the cost per pound by the total amount of sand he bought.

Pedro spent $31.05 on sand, which is answer choice B.
Hope that helped =)
Ok so in order to do that you need a calculator
The indicated sum is 350. The answer is 350 because the E or sigma is making you do (6j+2) ten times. Every time you do 6j+2 you start with j as 1 and add a 1 to j for every time you add. For example, [6(1)+2]+[6(2)+2]+[6(3)+2]...[6(10)+2].
Hope this helps.