Frank's father came home from San Francisco by airplane. He had to wait 1 hour and 45 minutes at the airport in San Francisco. Then Frank's father had to wait another 35 minutes while the plane was in Portland. How long did Frank's father spend waiting?

Frank's father waited 140 minutes all together

Step-by-step explanation:

Sorry if I'm wrong :/

23

step-by-step explanation:

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb