Answer:
6825
Step-by-step explanation:
From the equation, the series is a geometric series, such that
a = 5
r = 4
n = 6
sum of a geometric series is a(r^n - 1)/(r - 1)
therefore,
sum of the series is 5 x (4^6 - 1) / (4 - 1)
= 5 x (4096 - 1) / 3
= 5 x 4095 / 3
= 6825
The question mark is 100. It is a variable if you don't know
You could do y÷2-x to get x - half of y
No you do not. I think I will help.