The summation symbol means we use the variable i in the equation from the given range. In this case, we are given with the equation 3 i - 15 and i ranges from 2 to 7. The summation using simply the calculator is equal to -9. The answer to this problem is -9.
6) arc length = 2*PI*R* degree/360
arc length = 2 * PI * 3 * 65/360
= 6*PI x 65/360
= 13/12*PI
Answer = C
7) drawing the lines as given would make a T shape with B being the mid point, so the answer would be C
It would be: - 2 - (-10) = 5x - 12
= -2 + 10 = 5x - 12
= 8 + 12 = 5x
= x = 20 / 5
= x = 4
28 x 25 = $700
Answer: The class raises at least $700.
