Answer: m = $52
Explanation:
Tickets (t) = $8
Popcorn & Soda (s)= $5
Friends = 4
Since all friends bought the same thing the equation will be set as
4(t +s) = m OR 4t +4s = m
Using substitution, you plug each variable
t = 8 and s = 5
4((8) + (5)) = m
4(8+5) = m => 4(13) =m => 52=m
OR
4(8) + 4(5) = m => 32 + 20 = m =>
52 =m
Find the LCM (least common multiple) of the denominators, and use that as the denominator for the two fractions.
Ex.

LCM (3, 4) is 12

=
Answer: ![(-\infty, -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%20-4%5D)
Curved parenthesis at negative infinity
Square bracket at -4
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Work Shown:

The last inequality shown above is the same as saying 
Converting this to interval notation leads to the final answer of ![(-\infty , -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%20%2C%20-4%5D)
Note the use of a square bracket at -4 to include this endpoint. We can never include either infinity, so we always use a parenthesis for either infinity.
Sin⁻¹ √2 = 1/√2 = 1(√2) / (√2)(√2) = √2/2
The LCD here is 20. Thus, 1/4 = 5/20. The sum of 5/20 and 13/20 is 18/20, which can be reduced to 9/10.