If (x - 3) and (x + 7) are the factors of the trinomial x2 + ax – 21, what is the value of a?
A.)-3
Б.)-4
C.)7
Д.)4

Write the sentence as an equation. b increased by 281 is d

Can someone pls ! pls answer all. no explanation needed..

An optical inspection system is used to distinguish among different part types. the probability of a correct classification of any part is 0.92. suppose that three parts are inspected and that the classifications are independent. let the random variable x denote the number of parts that are correctly classified. determine the probability mass function of x. round your answers to four decimal places (e.g. 98.7654). x f(x) 0 1 2 3