每日一题

Mathematics

1/6(√k)-3=1-√k

What is the solution, rounded to the nearest tenth, to the equation above?

A.1.9
B.2.9
C.3.4
D.11.8

答案和解析

答案：D

解析：

Choice D is correct. Solve the equation by first isolating √k:

1/6√k-3=1-√k
1/6√k+√k=4
√k(1+1/6)=4
√k=24/7

Squaring both sides results in:
k=(24/7)^2=576/49

Next, substitute k=(24/7)^2 into the original equation:
1/6√[(24/7)^2]-3=1-√[(24/7)^2]
-17/7=-17/7

The solution to the equation is k=576/49≈11.8, rounded to the nearest tenth.
The solution is approximately 11.8.