All GRE Math Resources
Example Question #473 : Algebra
6/x = 9/19
none of these
none of these
(6)(19) = 9x
x = 38/3
Example Question #1 : How To Solve For A Variable As Part Of A Fraction
Example Question #45 : Algebraic Fractions
The numerator of a fraction is the sum of 4 and 5 times the denominator. If you divide the fraction by 2, the numerator is 3 times the denominator. Find the simplified version of the fraction.
Let numerator = N and denominator = D.
According to the first statement,
N = (D x 5) + 4.
According to the second statement, N / 2 = 3 * D.
Let's multiply the second equation by –2 and add itthe first equation:
–N = –6D
+[N = (D x 5) + 4]
–6D + (D x 5) + 4 = 0
–1D + 4 = 0
D = 4
Thus, N = 24.
Therefore, N/D = 24/4 = 6.
Example Question #46 : Algebraic Fractions
If , what is the value of ?
Start by cross multiplying to get the equation
Then simplify by subtracting from each side to get the solution,
Example Question #47 : Algebraic Fractions
If , then what is equal to?
We start by solving for x in by multiplying 4 and 15, which gives us .
Then substituting 60 for x in,
which equals 0.
Example Question #48 : Algebraic Fractions
If , and , what is the value of ?
Start by cross multiplying which gives us .
Simplify by dividing both sides by which gives us .
Isolate by dividing both sides by and then adding to both sides, which gives us .
Example Question #51 : Algebraic Fractions
If , and what is the value of ?
Start by cross multiplying which gives us
Divide both sides by 12 and simplify which gives us .
Since , we only take the positive square root as the solution, .