Question

If 3x−y=12, what is the value of 8x2y?

A) 212
B) 44
C) 82
D) The value cannot be determined from the information given.

Answer 1

ANSWER EXPLANATION: One approach is to express

8x2y

so that the numerator and denominator are expressed with the same base. Since 2 and 8 are both powers of 2, substituting 23 for 8 in the numerator of 8x2y gives

(23)x2y

which can be rewritten

23x2y

Since the numerator and denominator of have a common base, this expression can be rewritten as 2(3x−y). In the question, it states that 3x−y=12, so one can substitute 12 for the exponent, 3x−y, which means that

8x2y=212

The final answer is A.

Answer 2

actually values of two variables can not be found from a single equation .so,option D is correct....