Lisa is standing on a dock beside a lake. She drops a rock from her hand into the lake. After the rock hits the surface of the lake, the rock's distance from the lake's surface changes at a rate of −3 inches per second. If Lisa holds her hand 3 feet above the lake's surface, how far from Lisa's hand is the rock 3 seconds after it hits the surface.

what? ?

what type of question is thiss

step-by-step explanation:

step-by-step explanation:

0

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

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