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2 years ago

15

Help Math question Write ur answers

1 answer:

Ad libitum [116K]2 years ago

7 0

Answer:

this can be solved by simple unitary method

$time \: taken \: to \: remove \: \frac{5}{9} \: tons \: of \: dirt \: = 1 \: hr \\ time \: taken \: to \: remove \: \frac{31}{6} \: tons \: of \: dirt \: = \frac{31}{6} \times \frac{9}{5} \: hr \\ = \frac{93}{10}hr \\ = 9 \times \frac{3}{10} hr$

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Which statement is true? Select all that apply.

julsineya [31]

It’s b and c and i believe a

3 0

2 years ago

Write a quadratic function, in standard form, that fits the set of points. Solve it as a system of three equations. (-4, 9), (0,

Tresset [83]

Answer:

$\boxed{y=2x^2+4x-7}$

Step-by-step explanation:

Let the quadratic function be

$y=ax^2+bx+c$

We substitute $(-4,9)$ into the equation to obtain;

$9=a(-4)^2+b(-4)+c$

$\Rightarrow 9=16a-4b+c---(1)$

We substitute $(0,-7)$ to obtain;

$-7=a(0)^2+b(0)^2+c$

$\Rightarrow c=-7---(2)$

We finally substitute $(1,-1)$ to obtain;

$-1=a(1)^2+b(1)^2+c$

$\Rightarrow -1=a+b+c---(3)$

We put equation (2) into equation (1) to get;

$9=16a-4b-7$

$16a-4b=16$

$\Rightarrow 4a-b=4---(4)$

$\Rightarrow -1=a+b-7$

$\Rightarrow a+b=6---(5)$

We add equation (4) and (5) to get;

$4a+a=6+4$

$\Rightarrow 5a=10$

$\Rightarrow a=2$

We put $a=2$ into equation (5) to get;

$2+b=6$

$\Rightarrow b=6-2$

$\Rightarrow b=4$

The reqiured quadratic function is

$y=2x^2+4x-7$

7 0

2 years ago

In the diagram, the radius of the outer circle is

JulijaS [17]

the value of x is 8 cm.

<u>Step-by-step explanation:</u>

Correct Question : In the diagram, the radius of the outer circle is 2x cm and the radius of the inside circle is 6 cm. The area of the shaded region is 220π cm2. What is the value of x? Enter your answer in the box.

We have ,

the area of a circle = πr²

the outer circle area = $\pi(2x)^2 =4\pi x^2$

the inside circle area = $\pi (6)^2= 36\pi$

According to Question,

the outer circle area - the inside circle area = he shaded region

⇒ $\pi (4x^2)-36\pi =220\pi$

⇒ $x^2-9 =55$

⇒ $x^2=64$

⇒ $x =\sqrt{64}=8$

Therefore , the value of x is 8 cm.

5 0

2 years ago

Use the diagram below to name the following

Mrrafil [7]

1. Line a and line b
2. Segment VX and segment YZ
3. Ray WY and Ray WZ
4. Angle YWV and Angle XWZ
5. Plane D and Plane VWX

6 0

3 years ago

Darren's rectangle measures 3 1/3 units by 3 1/3 units. What is its area?

Andrei [34K]

Answer:

11 1/9

Step-by-step explanation:

3 1/3 x 3 1/3

= 10/3 x 10/3

= 100/9

= 11 1/9

4 0

2 years ago