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The charging standard of a taxi in a city is: the starting price is 5 yuan (that is, you need to pay 5 yuan if the distance is less than 3 km). After 3 km, every additional 0.5 km Charge 0.9 yuan (less than 0.5 km, calculated by 0.5 km), Mr. Li paid 19.4 yuan for taking this kind of taxi from a to B. how many kilometers is the farthest distance from a to B? It's the most!
(19.4-5) / (0.9x2) + 3 = 11km
On the circle of mathematics, trouble the teacher
As shown in the figure, circle O1 and circle O2 are circumscribed, AB and CD are two common tangents, and the extension lines of AB and CD intersect at p. if ∠ APC = 60 °, find the ratio of the radius of two circles of circle O1 and circle O2
According to the graph, mark letters as follows: PAB, po1o2, PCD. Suppose that the radius of circle O1 is r, the radius of circle O2 is r, connecting O1A and o2b, passing through O1 as O1h, perpendicular to o2b at h. in triangle o1o2h, the angle ho1o2 = 30 °, O1O2 = R + R, o2h = R-R, then: o2h = (1 / 2) o1o2r-r = (1 / 2) (R + R) r = 3R, then
In the spring of this year, Southwest China, such as Yunnan and Guizhou, encountered no drought for many years. In order to irrigate farmland in time, Fengshou Agricultural Machinery Co., Ltd. decided to support a total of 10 diesel generators (at least one for each type) with different power in Shangping village and 4, 3 and 2 pumps of the same type, each of which can pump water every hour All diesel generators and associated pumps are required to work for one hour at the same time to irrigate 32 mu of farmland. (1) the number of type a diesel generators is x, and that of type B diesel generators is y The hourly cost is 130 yuan, 120 yuan and 100 yuan respectively. How to arrange the number of three kinds of diesel generators, so as to pump water for irrigation as required and minimize the total cost of diesel generators?
(1) (1) the number of C-type diesel generators is 10-x-y; (2) the number of C-type diesel generators is 10-x-y; (2) the number of C-type diesel generators is 10-x-y, ∵ 4x + 3Y + 20-2x-2y = 32, ∵ 2x + y = 12, ∵ y = 12-2x, ∵ 10-x-y = (X-2), w = 130x + 120 (12-2x) + 100 (X-2) = - 10x +
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