Answer: 
Step-by-step explanation:
Given the following expression shown in the picture:
You need to use a process called "Ratinalization".
By definition, using Rationalization you can rewrite the expression in its simplest form so there is not Radicals in its denominator.
Then, in order to simplify the expression, you can follow the following steps:
<em>Step 1</em>. You need to multiply the numerator and the denominator of the fraction by , which is the conjugate of the denominator 
.
<em>Step 2</em>. Then you must apply the Distributive property in the numerator.
<em>Step 3</em>. You must apply the following property in the denominator: 
Therefore, applying the procedure shown above, you get:
<em>Step 4</em>. You can observe that the expression can be simplified even more. Since:
You get:
Using the slope - intercept relation, the required equation which models the scenario and Raul's speed are ;
- <em>y</em><em> </em><em>=</em><em> </em><em>-</em><em> </em><em>7.5x</em><em> </em><em>+</em><em> </em><em>15</em><em> </em>
- <em>4</em><em> </em><em>miles</em><em> </em><em>per</em><em> </em><em>hour</em><em> </em>
Time difference, Δt = 1.2 hours - 0.5 hours = 0.7 hours
Change in distance, Δd = 11.25 - 6 = 5.25 miles
Assuming a constant speed :
- Speed = (Δd ÷ Δt) = (5.25 ÷ 0.7) = 7.5 mi/hr
<u>Using the general form</u> :
At, x = 1.2 hours ;
Miles left, y = 6 miles
End point decreases by 7.5 mi/hr (-7.5 mi/hr)
Inputting the data into the equation :
6 = - 7.5(1.2) + c
6 = - 9 + c
c = 6 + 9 = 15 miles
<u>The expression in slope intercept form becomes</u> ;
<u>If Raul lives 5 miles closer to the beach</u> ;
<u>Time it will take Luis to get to the beach</u> :
- Time taken = (15 ÷ 7.5) = 2.5 hours
Distance Raul has to cover = 15 - 5 = 10 miles
To reach the beach after 2.5 hours ;
- Speed required = (10 ÷ 2.5) = 4 mi/hr
Therefore, Raul has to ride at 4 miles per hour for the plan to work.
Learn more :brainly.com/question/18405415
The answer to this is 5a-7
936936 is the perimeter and perimeter of a square is 4 times the length of one of the sides. therefore, you divide 936936 by 4 and get your answer, which is 234234.
