I am doing practice problems for a math class and I am stuck on how to work the following problems.?

Question

Problems:

1. In a class there are 25 males and 20 females. Find the ratio of males to females and reduce to lowest terms.

this is my answser 25:30 = 5:4 there are 5 males to every 4 females

2. Determine if (-1,-1), (0,0) and (4,5) are solutions to x<y-2

3. Graph the solution system of linear inequalties

y<-3 +4

y less than or equal to x +3

4. The formula for pressure P is p = 15 + (5d/11), where P is in pounds per square inch and d is depth in ft. Find P when d = 11 ft.

Answer 1

1. Yes, you&#039;re right.

2. Just plug in the values. The first number is the x value, the second is the y.

for (-1,-1): -1 &lt; -1-2 ==&gt; -1&lt;-3 TRUE!

for (0,0): 0&lt;0-2 ==&gt; 0&lt;-2 False!

for (4,5): 4&lt;5-2 ==&gt; 4&lt;3 False!

3. Just replace the inequality with equals, and graph it with a dotted line.

so: y&lt;-3+4 ==&gt; y&lt;1.

Lines with no x or no y are special cases. For only y, draw a dotted line horizontally at y=1. Now, you need to figure out which side to shade. Try (0,0). This gives 0&lt;1. This is true, so shade below the line, because any (and all) points below the line make the equation true.

For y≤x+3, pick any two points to make the equality true. Lets just pick x=0 and y=0. For x=0, plug in, and y=3. For y=0,  x=-3, by subtracting 3 from each side. If this seems hard, just try some other value for x, say -3, which would give y=0. Draw a solid line through the points (since this is an equality). Now, try a point on one side of the line, say (0,0), which is below and right of the line. It is true: 0≤3, so shade the portion to the bottom right of line.

4. Plug in d=11:

p = 15 + (5*11/11) = 15 + 5 = 20 pounds per square inch.

Answer 2

1. 5:4

2.

3.

4.65