Answer:
Step-by-step explanation:
27 ) 2x² - x - 1 = 0
2x² - 2x + x - 1 = 0
2x ( x - 1) + (x - 1) = 0
(x - 1)(2x + 1) = 0
x - 1 = 0 ; 2x + 1 = 0
x = 1 ; 2x = -1
x = -1/2
x = 1 ; -1/2
Option b
28) Area of a rectangle = 24 cm²
length * width = 24
(3x +2 )(2x -1) = 24
3x(2x -1) + 2(2x - 1) = 24
3x *2x - 3x *1 + 2*2x - 2*1 = 24
6x² -3x + 4x - 2= 24
6x² + x - 2 -24 = 0
6x² + x - 26 = 0
6x² -12x + 13x - 26 = 0
6x(x - 2) + 13(x - 2) = 0
(x -2)(6x +13) = 0
x = 2 {Ignore 6x + 13 as it gives negative value}
length = 3x + 2 = 3*2 + 2 = 6 + 2 = 8 cm
Width = 2x - 1 = 2*2 - 1 = 4 - 1 = 3 cm
29) Area of square = 900 cm²
Side² = 900
(5x)² = 900
25x² = 900
x² = 900/25
x² = 36
x = √36 = √6*6
x = 6 cm
30) base = b cm
height = b + 2
Area of triangle = 24 cm²
b(b + 2) = 24*2
b² + 2b = 48
b² + 2b - 48 = 0
b² - 6b + 8b - 48 = 0
b(b - 6) + 8(b - 6) = 0
(b - 6) (b + 8) = 0
b - 6 = 0 {Ignore b +8 = 0 as it gives negative value}
b = 6 cm
height = 6+ 2 = 8 cm
The volume of the region R bounded by the x-axis is: 
<h3>What is the volume of the solid revolution on the X-axis?</h3>
The volume of a solid is the degree of space occupied by a solid object. If the axis of revolution is the planar region's border and the cross-sections are parallel to the line of revolution, we may use the polar coordinate approach to calculate the volume of the solid.
In the graph, the given straight line passes through two points (0,0) and (2,8).
Therefore, the equation of the straight line becomes:
where:
- (x₁, y₁) and (x₂, y₂) are two points on the straight line
Thus, from the graph let assign (x₁, y₁) = (0, 0) and (x₂, y₂) = (2, 8), we have:
y = 4x
Now, our region bounded by the three lines are:
Similarly, the change in polar coordinates is:
where;
- x² + y² = r² and dA = rdrdθ
Now
- rsinθ = 0 i.e. r = 0 or θ = 0
- rcosθ = 2 i.e. r = 2/cosθ
- rsinθ = 4(rcosθ) ⇒ tan θ = 4; θ = tan⁻¹ (4)
- ⇒ r = 0 to r = 2/cosθ
- θ = 0 to θ = tan⁻¹ (4)
Then:
Learn more about the determining the volume of solids bounded by region R here:
brainly.com/question/14393123
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Answer:
ask to your teachers and you will be finish the work
