Thay x = 2 (thỏa mãn điều kiện) vào B ta có: B = \frac{{ - 10}}{{2 - 4}} = \frac{{ - 10}}{{ - 2}} = 5

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side