# Tutor profile: Rebecca W.

## Questions

### Subject: SAT

If t > 0 and (t^2) − 9 = 0, what is the value of t?

The correct answer is 3. To solve for t, factor the left side of (t^2) − 9 = 0, giving (t − 3)(t + 3) = 0. Terefore, either t − 2 = 0 or t + 2 = 0. If t − 3 = 0, then t = 3, and if t + 3 = 0, then t = −3. Since it is given that t > 0, the value of t must be 3. Another way to solve for this is to add 9 to both sides of (t^2) − 9 = 0, giving (t^2) =9. Then, taking the square root of the left and the right side of the equation gives t=±√9=±3. Since it is given that t>0, the value of t must be 3.

### Subject: Organic Chemistry

What is the reason amides are not naturally found in the human body?

Compared to amines, amides are very weak bases. This relative lack of basicity is explained by the electron-withdrawing nature of the carbonyl group where the lone pair of electrons on the nitrogen is delocalized by resonance.

### Subject: Pre-Algebra

What is 56.789 divided by 0.34?

The answer to the question above is 167.03.

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