Find x, given 5(√5)(x+5) = (√5)(2x+7)
2017
Find x, given 5(√5)(x+5) = (√5)(2x+7)
- A.
x = −1
- B.
x = 0
- C.
x = 1
- D.
x = −2
Attempted by 47 students.
Show answer & explanation
Correct answer: B
Given:
5(√5)^(x+5) = (√5)^(2x+7)
Write 5 as:
5 = (√5)²
So,
(√5)² × (√5)^(x+5) = (√5)^(2x+7)
Using the law:
aᵐ × aⁿ = aᵐ⁺ⁿ
(√5)^(x+7) = (√5)^(2x+7)
Since the bases are the same, equate the powers:
x + 7 = 2x + 7
x = 0