: Đẳng thức nào sau đây đúng ?
A. cos4x – sin4x = 2-cos2x B. cos4x – sin4x = 1+2sin2x

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.

Find the difference (8ab+a+2) - (3ab+6)

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.