Please help I don’t understand this

25 hours

Step-by-step explanation:

Let r = rate, t = time

From 1st sentence,

5r x 12 = 3

60r = 3

r = 3/60 = 1/20

From the next,

4r x t = 5

4 x 1/20 x t = 5

4/20t = 5 = 25

10a^3+277a^2-132a-792

step-by-step explanation:

(2a+11)(5a-12)(foil)

=10a^2-24a+55a-132 =10a^2+31a-132

(10a^2+31a-132)(a+6)

=10a^3+60a^2+31a^2+186a^2-132a-792 =10a^3+277a^2-132a-792

i hope this is what you are looking for : )