+0

# Help

0
130
2
+166

Assume $$0 < r < 3$$. Below are five equations for $$x$$. Which equation has the largest solution $$x$$?

$$\textbf{(A)}\ 3(1 + r)^x = 7\qquad \textbf{(B)}\ 3(1 + r/10)^x = 7\qquad \textbf{(C)}\ 3(1 + 2r)^x = 7 \textbf{(D)}\ 3(1 + \sqrt {r})^x = 7\qquad \textbf{(E)}\ 3(1 + 1/r)^x = 7$$

Jul 30, 2019
edited by FlyEaglesFly  Jul 30, 2019

#1
+28202
+1

Since the numbers in brackets are all greater than 1 for 0 < r < 3, the smallest value of the bracketed term will require the largest value of x.

The smallest is (1 + r/10), so (B) will require the largest x.

Jul 30, 2019
edited by Alan  Jul 30, 2019
edited by Alan  Jul 30, 2019
#2
+166
0

I put all five now

Jul 30, 2019