Im actually pretty sure its C because 4 to the power of 2 is 16 and then add those too up 16+25=41
I will do (a) only.
6rt - 3st + 6ru - 3su
6rt - 3st = 3t(2r - s)
6ru - 3su = 3u(2r - s)
Answer: (3t + 3u)(2r - s)
Do the rest likewise.
The best equation would be A.
with A you get to calculate what is the value of $.
8 + $ = 10 (10 is the total value of your receipt and 8 is the price of pizza)
$ = 10 - 8 (we transfer the price of pizza on the other side to the total amount of your receipt and calculate the remaining amount)
$ = 2
We see that the remaining amount is 2$, which means the salad cost s2$ :)
To find A' they used the rule of multiplication, which is:
the derivative of a product of two terms is the first term times the derivative of the second term plus the second term times the derivative of the first.
To find b' they just isolated b'
