a math problem from SAT

The following is a problem from a SAT practice test:

If 6x + 1/x = 5, then x = ?

  1. -1/6
  2. 1/6
  3. 1/4
  4. 1/2
  5. 2

You can try each number but you can also solve the problem on your own first and find the match for your answers.

How is how to solve it:

Multiply both sides of the equal sign with x so the equation becomes:

6x+1=5x

6x2-5x+1=0

Factor:

(2x-1)(3x-1)=0

X can be either ½ or 1/3.

The correct answer is D.

 

The following is a question from a SAT practice test:

The average (arithmetic mean) of 3 numbers is 22 and the smallest of these numbers is 2. If the two remaining numbers are equal, what is the value of each of the remaining numbers?

  1. 22
  2. 32
  3. 40
  4. 64
  5. 66

Here is how to solve for the answer:

The average of the 3 numbers is 22 so the sum of them should be:

22 x 3=66

One of the numbers is 2 so the sum of the other two numbers should be:

66-2=64

Since the other two numbers have the same value the value of each number should be:

64÷2=32

The correct answer is  B.