What two numbers added together equal 6, but when multiplied equal -40. my problem is 'a+b=6, ab=-40'

Suppose i flip two identical coins. what is the probability that i get one head and one tail?

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83