Kristen completed 42 km. We will imagine that she ran all 6 hours. => 9 * 6 =54 km which is more than she actually completed. So we will find a 9 Multiple less than 42 km and that will be 36 km. (9 * 4 = 36 km completed by running) and the rest until 42 were completed by walking (3 * 2 = 6; 6 + 36 =42).
A three-dimensional object
<span>This question, in my opinion, is not well stated. If f(x) = √x, as the question statement seems to say, then the domain is not x<7. Rather, the domain is x≥0.
If f(x) is not the square root function, but say f(x) = √(7-x) then the domain is x≤7, and for this function then the appropriate answer is d), since the x-term inside the radical has a negative coefficient.</span>