Answer:
Step-by-step explanation:
39 cars every 3 hrs.......that means (39/3) = 13 cars every hr
and if its 13 cars every hr....in 7 hrs, there will be (7 * 13) = 91 cars <==
you can either do it that way....the unit rate way...OR
you can set it up as a proportion...
39 cars to 3 hrs = x cars to 7 hrs...
39 / 3 = x / 7....cross multiply
(3)(x)= (39)(7)
3x = 273
x = 273/3
x = 91 <====
either way, u get the correct answer
Answer:
32 seconds
Step-by-step explanation:
For some number of seconds (s), Tess's essay length (t) will be ...
t = 42 +1.3s
and Margo's essay length (m) will be ...
m = 122 -1.2s
We will have t > m when ...
t > m
42 +1.3s > 122 -1.2s
2.5s > 80 . . . . . . . . add 1.2s-42
s > 32 . . . . . . . . . . . divide by 2.5
After 32 seconds, Tess's essay will exceed Margo's in length.
Answer:

Step-by-step explanation:
Given

Required
Determine an equivalent expression
In trigonometry:

In 

Substitute
for
in 


Hence, the equivalent expression is: 
We can use completing the square.We add 16 and subtract 7 to both sides. Now we get m^2+8m+16=9. The left sides becomes (m+4)^2=9. Taking the square root of both sides and subtracting 4 we get -1 and -7.