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3 years ago

Which property explains why these two expressions are equal?

1 answer:

7 0

Re-written, I believe the equation is:

(W+23)+5=W+(23+5)

With this, the parenthesis have nothing multiplying into it, so we can drop the parenthesis to get:

W+23+5=W+23+5
Which is the same thing.

So I'd assume it is the Associative property, because you are combining the like terms of 23 and 5.

Hope this helps!

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Please help I’ll make you a branliest!!!!!!!

masya89 [10]

Answer:

2 answer is right

Step-by-step explanation:

I think

7 0

3 years ago

Mario start collecting stamps in January and buys 12 stamps each month.Karen starts collecting stamps in July and buys 18 starts

Goryan [66]

Answer:

12 months

Step-by-step explanation:

Given that:

Mario:

12 stamps per month

Since January

Karen :

18 stamps per month

Starts on july

Number of stamps collected by Mario till the end of June :

12 * 6 = 72 stamps

For Mario :

72 + 12x

For karen:

18x

Where x is the number of months after karen starts :

Equate both equations

72 + 12x = 18x

72 = 18x - 12x

72 = 6x

x = 72/6

x = 12

After 12 months

Number of months after karen starts, will they have same amount of stamp

7 0

3 years ago

the height h(t) of a trianle is increasing at 2.5 cm/min, while it's area A(t) is also increasing at 4.7 cm2/min. at what rate i

nekit [7.7K]

Answer:

The base of the triangle decreases at a rate of 2.262 centimeters per minute.

Step-by-step explanation:

From Geometry we understand that area of triangle is determined by the following expression:

$A = \frac{1}{2}\cdot b\cdot h$ (Eq. 1)

Where:

$A$ - Area of the triangle, measured in square centimeters.

$b$ - Base of the triangle, measured in centimeters.

$h$ - Height of the triangle, measured in centimeters.

By Differential Calculus we deduce an expression for the rate of change of the area in time:

$\frac{dA}{dt} = \frac{1}{2}\cdot \frac{db}{dt}\cdot h + \frac{1}{2}\cdot b \cdot \frac{dh}{dt}$ (Eq. 2)

Where:

$\frac{dA}{dt}$ - Rate of change of area in time, measured in square centimeters per minute.

$\frac{db}{dt}$ - Rate of change of base in time, measured in centimeters per minute.

$\frac{dh}{dt}$ - Rate of change of height in time, measured in centimeters per minute.

Now we clear the rate of change of base in time within (Eq, 2):

$\frac{1}{2}\cdot\frac{db}{dt}\cdot h = \frac{dA}{dt}-\frac{1}{2}\cdot b\cdot \frac{dh}{dt}$

$\frac{db}{dt} = \frac{2}{h}\cdot \frac{dA}{dt} -\frac{b}{h}\cdot \frac{dh}{dt}$ (Eq. 3)

The base of the triangle can be found clearing respective variable within (Eq. 1):

$b = \frac{2\cdot A}{h}$

If we know that $A = 130\,cm^{2}$ , $h = 15\,cm$ , $\frac{dh}{dt} = 2.5\,\frac{cm}{min}$ and $\frac{dA}{dt} = 4.7\,\frac{cm^{2}}{min}$ , the rate of change of the base of the triangle in time is:

$b = \frac{2\cdot (130\,cm^{2})}{15\,cm}$

$b = 17.333\,cm$

$\frac{db}{dt} = \left(\frac{2}{15\,cm}\right)\cdot \left(4.7\,\frac{cm^{2}}{min} \right) -\left(\frac{17.333\,cm}{15\,cm} \right)\cdot \left(2.5\,\frac{cm}{min} \right)$

$\frac{db}{dt} = -2.262\,\frac{cm}{min}$

The base of the triangle decreases at a rate of 2.262 centimeters per minute.

6 0

3 years ago

If the graph of an equation is symmetric with respect to the y-axis and 6 is an x-intercept, name another x-intercept

givi [52]

-6 because for every value (x,y) there is another value (-x,y) so for the value (6,0) there must also be a value (-6,0). That is what the definition of y-axis symmetry is, it is also known as being an "even" function if it has this type of symmetry. Look at the graph of y=(x^2)-36 to see how this works.

4 0

3 years ago

Help Please? Solve for x. x − 2.7 ≥ 10.3 Solve for x. −0.84x ≤ 168

stiks02 [169]

For the first one, we add 2.7 to both sides to get x≥13. Next, we divide both sides by -0.84 to get x≥ 168/-0.84. SInce we multiplied or divided by a negative number, we switch the sign around and end up with x≥200

4 0

3 years ago