math
posted by Melissa .
a student plants a seed, after the speed sprouts the student monitors the growth of the plant by measuring its height every week, the height after each of the first tree wees was 7mm , 20mm, and 33mm, respectively, if this pattern of growth continuesinwhat week will the plant be more than 100mm tall

looks like d = 13
what term = 100?
7 + 13(n1) = 100
13n  13 = 93
13n = 106
n = 106/13 = 8.1
in 8 weeks the tree will be slightly short of the 100
( term(8) = a+7d = 7 + 91 = 98 )
So it will be more than 100 mm tall in the 9th week