Is sqrt(x) a prime number?
(1)|3x-7| =2x+2
(2)x^2=9x
[spoiler]OA:C[/spoiler]
(1)|3x-7| =2x+2
(2)x^2=9x
[spoiler]OA:C[/spoiler]
What you think, you become.
1) We can rewrite this absolute value as two different equations: either 3x - 7 = 2x + 2, or 3x - 7 = -2x - 2.
3x = 2x + 9
x = 9
5x = 5
x = 1
x could equal 9 or 1, so the square root of x could be 3 or 1. 3 is prime, 1 is not; insufficient.
2) Easy to assume that 9 is the only value that works here, but always watch out for 0 on exponent problems! In this case, 0 satisfies statement 2) just as well. So, x could be 9 or 0, and sqrt x could b 3 or 0--prime or non-prime. Insufficient.
Combined: 9 is the only value that satisfies both equations, so the answer is (C), both statements together are sufficient to answer the question.
