Answer:
4
Step-by-step explanation:
Explanation:
D
=
d
2
=
b
2
−
4
a
c
=
100
+
96
=
196
-->
d
=
±
14
There are 2 real roots:
x
=
−
b
2
a
±
d
2
a
=
10
6
±
14
6
=
5
3
±
7
3
The positive real root is :
12
3
=
4
Answer:
Part one: The function rule for the area of the rectangle is A(x) = 3x² - 2x
Part two: The area of the rectangle is 8 feet² when its width is 2 feet
Step-by-step explanation:
Assume that the width of the rectangle is x
∵ The width of the rectangle = x feet
∵ The length of the rectangle is 2 ft less than three times its width
→ That means multiply the width by 3, then subtract 2 from the product
∴ The length of the rectangle = 3(x) - 2
∴ The length of the rectangle = (3x - 2) feet
∵ The area of the rectangle = length × width
∴ A(x) = (3x - 2) × x
→ Multiply each term in the bracket by x
∵ A(x) = x(3x) - x(2)
∴ A(x) = 3x² - 2x
∴ The function rule for the area of the rectangle is A(x) = 3x² - 2x
∵ The rectangle has a width of 2 ft
∵ The width = x
∴ x = 2
→ Substitute x by 2 in A(x)
∵ A(2) = 3(2)² - 2(2)
∴ A(2) = 3(4) - 4
∴ A(2) = 12 - 4
∴ A(2) = 8
∴ The area of the rectangle is 8 feet² when its width is 2 feet
Answer:
y = -1/2x - 4
Step-by-step explanation:
In the figure below
1) Using the theorem of similar triangles (ΔBXY and ΔBAC),
Where
Thus,
thus, BC = 7.5
2) BX = 9, BA = 15, BY = 15, YC = y
In the above diagram,
Thus, from the theorem of similar triangles,
solving for y, we have
thus, YC = 10.
