The corresponding point of a rational number on the number axis is a. move point a three unit length to the left and then two unit length to the left to get point B. the absolute value of the number corresponding to point B is equal to that of point A. what is the corresponding number of point a?

The corresponding point of a rational number on the number axis is a. move point a three unit length to the left and then two unit length to the left to get point B. the absolute value of the number corresponding to point B is equal to that of point A. what is the corresponding number of point a?

Let the number corresponding to point a be x, then the number corresponding to point B x-3-2 = X-5, and the absolute value of the number corresponding to point B and the number corresponding to point a are equal, | x | = | X-5 |, the solution is: x = 2.5

The length of a train is 300m. If a person and a train are going in the same direction, the whole train will pass by him after 18S; if the person and a train are going in opposite direction, the whole train will pass by him after 15s, and the speed of the person and the train can be calculated

Let the speed of man and train be XM / s and YM / s respectively. According to the meaning of the question, we get: 18 (Y-X) = 30015 (x + y) = 300, and the solution is: x = 53Y = 553, then the speed of man and train are 53m / S and 553m / s respectively

As shown in the figure, in the acute angle △ ABC, CD and be are the heights on the sides of AB and AC respectively, and CD and be intersect at a point P. if ∠ a = 50 °, then ∠ BPC = ()
A. 150°B. 130°C. 120°D. 100°

∧ be ⊥ AC, CD ⊥ AB, ∧ ADC = ∠ AEB = 90 °, ∧ BPC = ∠ DPE = 180 ° - 50 ° = 130 °. Therefore, B is selected