so the basic formula for this d = rt
where d is the distance , r is the speed and t
is time
3800 – 120t = 520 + 40t ( this is the altitude
of each plane are equal)
Solve for t
T = 20.5 min time it takes for the planes to be
at the same altitude
3800 – 120(20.5) = 1340 ft
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He will need to save for 40 weeks
it would be 16 times larger
What you want to do here is plug 2 in for x. when a question asks you to evaluate a certain equation at a certain number, it's just asking you to plug the value in for your variable. i'm assuming that 12x + 8 is meant to be set over 4 as a fraction.
(12(2) + 8)/4 ... figure out the top first. 12*2 = 24, 24 + 8 = 32.
32/4 = 8, so your correct choice is D.
