How to evaluate a fraction
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ACT Math › How to evaluate a fraction
Evaluate the following equation when  and round your answer to the nearest hundredth.
Explanation
1. Plug in  wherever there is an 
 in the above equation.
2. Perform the above operations.
Solve 
0
–1
no solution
infinitely many solutions
Explanation
The common denominator of the left side is x(x–1). Multiplying the top and bottom of 1/x by (x–1) yields




Since this statement is true, there are infinitely many solutions.
Simplify:
Explanation
Begin by simplifying the numerator and the denominator.
Numerator
 has a common denominator of 
. Therefore, we have:
Denominator
 has a common denominator of 
. Therefore, we have:
Now, reconstructing our fraction, we have:
To make this division work, you multiply the numerator by the reciprocal of the denominator:
If 3x = 12, y/4 = 10, and 4z = 9, what is the value of (10xyz)/xy?
10
4 1/2
360
160
22 1/2
Explanation
Solve for the variables, the plug into formula.
x = 12/3 = 4
y = 10 * 4 = 40
z= 9/4 = 2 1/4
10xyz = 3600
Xy = 160
3600/160 = 22 1/2
For this question, the following trigonometric identities apply:
,
Simplify: 
Explanation
To begin a problem like this, you must first convert everything to  and 
 alone. This way, you can begin to cancel and combine to its most simplified form.
Since  and 
, we insert those identities into the equation as follows.
From here we combine the numerator and denominators of each fraction together to easily see what we can combine and cancel.
Since there is a  in the numerator and the denominator, we can cancel them as they divide to equal 1. All we have left is 
, the answer.
If  , 
, and 
, find the value of 
.
Explanation
In order to solve , we must first find the values of 
, 
, and 
 using the initial equations provided. Starting with 
:
Then:
Finally:
With the values of , 
, and 
 in hand, we can solve the final equation:
Simplify: 
None of the other answer choices are correct.
Explanation
Recall that dividing is equivalent multiplying by the reciprocal. Therefore, ((x - 4) / (1 / 2)) / (1 / (x + 4)) = ((x - 4) * 2) * (x + 4) / 1.
Let's simplify this further:
(2x – 8) * (x + 4) = 2x2 – 8x + 8x – 32 = 2x2 – 32
If  then which of the following is equal to 
?
Explanation
To raise  to the exponent 
, square 
 and then take the cube root.
Simplify:
Explanation
Begin by simplifying the numerator.
 has a common denominator of 
. Therefore, we can rewrite it as:
Now, in our original problem this is really is:
When you divide by a fraction, you really multiply by the reciprocal:
If  pizzas cost 
 dollars and 
 sodas cost 
 dollars, what is the cost of 
 pizzas and 
 sodas in terms of 
 and 
?
Explanation
If 10 pizzas cost x dollars, then each pizza costs x/10. Similarly, each soda costs y/6. We can add the pizzas and sodas together by finding a common denominator: