Please help me by checking the following answers for me(There are 3 problems that I need someone to check).

Question

3. A student is attempting to solve the equation below for the variable x. Which of the statements below best applies to the mathematical work shown?

Given √(4x-6)=12, I square both sides, so (√4x)^2-6=〖12〗^2, or 4x -6 = 144. I can then solve for x, yielding x = 37 1/2 as my final answer.

A. The student did not correctly square both sides of the equation. - (This is my second answer.)

B. The student did not properly isolate the variable after squaring both sides of the equation.

C. The student omitted a negative solution to the equation.

D. The mathematical work is correct. - (I know it is not this because I got it wrong.)

4. Solve for x.

〖5x〗^2+3=-122

A. No solution. - (This is my second answer.)

B. -5 - (I know it is not the answer because I got it wrong.)

C. ±5

D. ±25

9. The acceleration of an object can be described by the equation a= 2d/t^2, where a is acceleration, d is the distance, and t is time. If an object accelerates at a rate of 2 m/s^2 for 10 meters, what is the total time elapsed?

A. 1/10 seconds - (This is my second answer.)

B. √(1/10) seconds

C. √10 seconds

D. 10 seconds - (I know it is not answer because I got it wrong.)

Please check them to see if I am correct. Any help will really be appreciated! :)

Answer 1

For 3, I don't see anything wrong with the work unless the initial equation is supposed to be sqrt(4x)-6=12 in which case the squaring wasn't done correctly, but based off what I see there D IS correct. For 4, A is the correct answer. You cannot take the square root of a -ve number. For 5, the correct answer is C. you have 2(10)/t^2=2, which leads to 20=2t^2. Then, 10=t^2 which therefore leaves t=sqrt(10)

Answer 2

Thank you, Dayton! :)