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2 years ago

Set up equations and solve them to find the unknown numbers in the following cases:

Mathematics

1 answer:

noname [10]2 years ago

3 0

Answer:

the answer is 21

Step-by-step explanation:

the number she thinks of is 21 add 21 + 19 to get 40.

divide 40 by 5 to get 8.

You might be interested in

Drag a description to match each equation.

AnnZ [28]

Given:

The descriptions and equations. The equations are

$y=4x$

$y=x+4$

To find:

The correct description for each equation and match them.

Solution:

We know that, "+" is used for more and "×" is used for times.

Additive: y is 4 more than x.

$y=x+4$

Additive: x is 4 more than y.

$x=y+4$

Multiplicative: y is 4 times x.

$y=4x$

Multiplicative: x is 4 times y

$x=4y$

Therefore, the correct description for the equation $y=4x$ is "Multiplicative: y is 4 times x " and the correct description for the equation $y=x+4$ is "Additive: y is 4 more than x. "

4 0

3 years ago

In a bag, there are 25 marbles. 8 are red and the rest are green. If there are 100 marbles in. a bag, how many are red? *

Sophie [7]

Answer:

32 marbles are red.

Step-by-step explanation:

Think of a quarter, 4 of them equal a dollar.

25 x 4 = 100

So, you will multiply 8 by 4.

8 x 4 = 32

4 0

3 years ago

A dish tv satellite dish is the shape of a paraboloid. the dish is 36 inches wide, and 8 inches deep. how many inches should the

MrRa [10]

Refer to the diagram shown below. It shows a vertical cross-section of the paraboloid through its axis of symmetry.

Let the vertex of the parabola be at the origin. Then its equation is of the form
y = bx²

Because the parabola passes through (18,8), therefore
8 = b(18²)
b = 0.02469
The parabola is y = 0.02469x².

The receiver should be placed at the focal point of the paraboloid for optimal reception.
The y-coordinate of the focus is
a = 1/(4b) = 1/0.098765 = 10.125 in

Answer: The receiver is located at 10.125 inches from the vertex.

4 0

3 years ago

What's the volume? I honestly just need the formula.

Arturiano [62]

Answer:

$v=364.5\ m^3$

Step-by-step explanation:

Volume Of A Regular Solid

When a solid has a constant cross-section, the volume can be found by multiplying the area of the base by the height. The area of a trapezium is

$\displaystyle A_t=\frac{b_1+b_2}{2}h$

where $b_1$ and $b_2$ are the lengths of the parallel sides and h the distance between them.

The figure shows a solid with a trapezoid as the constant cross-section and a height x. The volume of the solid is

$\displaystyle v=A_t\ x$

$\displaystyle v=\frac{b_1+b_2}{2}\ h\ x$

The image doesn't explicitly say if the length of 4.5 is the height of the trapezium or the length of that side. We'll assume the first, so our data is:

$\displaystyle b_1=7m,\ b_2=11m,\ h=4.5m,\ x=9m$

We now compute the volume

$\displaystyle v=\frac{7+11}{2}.(4.5)(9)=364.5$

$\boxed{\displaystyle v=364.5\ m^3}$

8 0

3 years ago

What is 4/25 as a mixed number

yaroslaw [1]

6 would be the answer

5 0

3 years ago