Question 227769: PLEASE HELP ME SOLVE THESE PROBLEMS:
1. A SQUARE AND RECTANGLE HAVE EQUAL AREAS. IF THE RECTANGLE IS 36 BY 16, WHAT IS THE SIDE OF A SQUARE?
2.IN A SOCIAL HALL OF A BUILDING, THERE ARE 150 SEATS ARRANGED IN ROWS WITH 5 MORE SEATS PER ROW THAN THE NUMBER OF ROWS. HOW MANY SEATS ARE THERE IN EACH ROW?
THANK YOU!!! I REALLY APPRECIATE IT...
Answer by drj(1380) (Show Source):
You can put this solution on YOUR website! Problem 1. A SQUARE AND RECTANGLE HAVE EQUAL AREAS. IF THE RECTANGLE IS 36 BY 16, WHAT IS THE SIDE OF A SQUARE?
Step 1. The area of a rectangle A=36*16=576 (area=base*height}}}
Step 2. The square has equal sides where we let s be the side which is equal to the base and height so A=s*s=s^2.
Step 3. The areas are equal in Steps 1 and 2. Then
Step 4. Take the square root to both sides of the equation or .
Step 5. ANSWER: The side of the square is 24.
Problem 2. IN A SOCIAL HALL OF A BUILDING, THERE ARE 150 SEATS ARRANGED IN ROWS WITH 5 MORE SEATS PER ROW THAN THE NUMBER OF ROWS. HOW MANY SEATS ARE THERE IN EACH ROW?
Step 1. Let n be the number of rows.
Step 2. Let n+5 be the number of seats per row.
Step 3. Then, n(n+5)=150 since there are 150 seats.
Step 4. Subtract 150 to both sides of equation in Step 3.
Step 5. To solve, use the quadratic equation given as
where a=1, b=5, and c=-150
Solved by pluggable solver: SOLVE quadratic equation with variable |
Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.
First, we need to compute the discriminant : .
Discriminant d=625 is greater than zero. That means that there are two solutions: .


Quadratic expression can be factored:

Again, the answer is: 10, -15.
Here's your graph:
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Selecting the positive solution of and and note the product is 150 seats.
Step 6. ANSWER: The number of seats in each row is 15 seats.
I hope the above steps were helpful.
For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.
And good luck in your studies!
Respectfully,
Dr J
http://www.FreedomUniversity.TV
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