Solve for x. x2 + 4x - 21 = 0 a. -3, -7 b. -3, 7 c. 3, -7 d. 3, 7

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?

Mr. thompson took five of his children to the bowling alley the cost for children 12 and older is 350 the cost of four children under 12 inch to 25 he spent a total of 1625 how many of his children are 12 and order