20
practice examMultiple Choice

Practice Exam

Question 20 • Mathematics III

If 5 plus 20 times 2 raised to the 2 minus 3 x power is equal to 10 times 2 raised to the negative 2 x power plus 5 , what is the value of x ?

Answer
A
negative 2
B
3
C
2
D
negative 3

Explanation

Subtract 5 from both sides to get 20·2^(2−3x) = 10·2^(−2x). Divide by 10 and combine powers of 2: 2^(3−3x) = 2^(−2x). Since the bases are equal, set the exponents equal: 3−3x = −2x, which gives x = 3. The correct choice is 3.

AI-written and checked against the verified answer.

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