Question

4. Which of the following equation represent quadratic?

A. The cost of each pen is Php 8.50. How many pens can be bought by Php 850?
B. The length of a field is 2 m more than twice its width and its area is 24 m2.
C. The length of the rectangular room is 3 more than the width and its area is at least 56m2.
D. The length of a wall is 8 m more than its width. If the area of the wall is less than 40 m2.

5. What are the dimensions of the largest rectangular field that can be enclosed with 100 m of wire?
A. 24 m x 26 m
B. 25 m x 25 m
C. 50 m x 50 m
D. 50 m x 25 m​

Answer 1

Explanation:

4) B , C and D represents the quadratic equation.

B) width = w

length = l = 2w + 2

Area = 24 square m

l *w = 24

(2w + 2)*w = 24

2w*w + 2w = 24

2w² + 2w - 24 = 0

Divide the entire equation by 2

w² + w - 12 = 0

C) width = w

Length = w + 3

Area = 40 m²

(w + 3 ) *w = 56

w*w + 3*w = 56

w² + 3w - 56 = 0

D) Width = w

Length = w + 8

Area = 40

(w + 8)*w = 40

w² - 8w - 40 = 0

5) B) 25 * 25

25 *25 gives the largest area that has its perimeter 100