X^2 + 10 = 35 when x = -5
x + x + x = 3x = -15 when x = -5.
The answer is B because part A just restates the first equation, and Part C determines which is greater. If you want to determine the difference between the two when x = -5, part B is the best answer because it subtracts the product of one of them from the other.
90 attempts are made and only one third are successful. Multiply the attempts by successes and you get 30 successful shots (90 x 1/3= 30).
This answer is c (x-4)(x+4)
Actually, you have to find four missed terms of geometrical sequence. Denote
and r - ratio, then
.
Since 
, you have that 
, then
.
Now substitude r=2 in each of unknown 4 terms:
.
Answer: four geometric means between 25 and 800 are 50, 100, 200, 400.
