Last year, 150 cases were reported of a new infectious disease. it has been predicted that the number will double every year. how many cases will be reported in the ninth year?

38,400

Step-by-step explanation:

This is  a geometric sequence requiring that the 9th term be computed. The nth term of a geometric sequence is given as

Tn = ar^n-1

where Tn is the nth term, a is the first term, r is the common ratio of then sequence

r = T2/T1

where T2 and T1 are the second and first terms respectively

Given that last year, 150 cases were reported of a new infectious disease. It has been predicted that the number will double every year. It means that

a = 150, r = 2

therefore, the 9th term which is the value in the 9th year

= 150 * 2^9-1

= 150 * 256

= 38,400

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.