SAT Math · Nonlinear equations in one variable · medium
What value of x satisfies 8^x+1 = 32^x-2?
What value of satisfies ?
Answer and explanation
Answer: A: 13/2
Rewrite both sides with the same base. Since and , the equation becomes . Equal bases with equal values mean the exponents are equal: . Subtract and add 10: , so , choice A. Choice B () results from a sign slip, using or subtracting 10 incorrectly. Choice C (2) is the number inside the parentheses. Choice D (5) comes from the same mistake, ignoring the factor of 3 and 5 on the exponents, or mismatching bases.
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