Here is the equation:

You need to find f(3). To do that, substitute all the x's with 3:

The first thing you need to do is multiply 4 by 3. Multiply:

Here is your new equation:

To get your answer, you need to add 12 and 1. Add:

That means:

<em>If you have any questions, feel free to ask in the comments! :)</em>
Answer:
d = 5,35 ft
Step-by-step explanation: See annex
Figure in annex is clear,
sin ∠42⁰ = d / 8
And
sin ∠42⁰ = 0.669
d/8 = 0,669
d = 0,669*8
d = 5,35 ft
Percent of students brought their lunch from home is 100-24= 76%
So, total students are in the six grade is
190 x 100/76 = 250 students
Here's the link to the answer.. 69.08