That is to say, the distance from A to B = the distance from B to A.
According to the meaning of the question,10 (3+u) = the distance from b to a.
The distance from b to a
Then 10 (3+u) < 12 (u-3)
30+ 10u< 12u-36
That is, u & gt33/h.
Question 2. Suppose you buy a breeding rabbit, then one year later, Lao Zhang has (a+2) rabbits and Lao Li has (2a- 1) rabbits.
Lao Zhang does not exceed 2/3 of the number of rabbits raised by Lao Li. Then (a+2)≤2/3(2a- 1).
Denominator 3(a+2)≤2(2a- 1)
That is 3a+6≤4a-2.
a≥8
When a=8 (a+2)=2/3(2a- 1), Lao Zhang is exactly 2/3 of Lao Li's rabbit breeding.
So Lao Zhang bought at least eight breeding rabbits a year ago.