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3 years ago

What is the value of a?

Mathematics

1 answer:

Annette [7]3 years ago

8 0

Answer:

Step-by-step explanation:

Look at the picture.

The formula of an area of a trapezoid is:

$A=\dfrac{b_1+b_2}{2}\cdot h$

$b_1,\ b_2$ - bases

$h$ - height

We have:

$A=128,\ b_1=a+2,\ b_2=a-2,\ h=8$

Substitute:

$128=\dfrac{a+2+a-2}{2}\cdot8\\\\128=\dfrac{2a}{2}\cdot8$

$128=8a$ divide both sides by 8

$16=a\to a=16$

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An object is propelled upward from the top of a 300 foot building. The path that the object takes as it falls to the ground can

serg [7]

Answer:

As per the statement:

The path that the object takes as it falls to the ground can be modeled by:

h =-16t^2 + 80t + 300

where

h is the height of the objects and

t is the time (in seconds)

At t = 0 , h = 300 ft

When the objects hit the ground, h = 0

then;

-16t^2+80t+300=0

For a quadratic equation: ax^2+bx+c=0 ......[1]

the solution for the equation is given by:

$x = \frac{-b\pm \sqrt{b^2-4ac}}{2a}$

On comparing the given equation with [1] we have;

a = -16 ,b = 80 and c = 300

then;

$t= \frac{-80\pm \sqrt{(80)^2-4(-16)(300)}}{2(-16)}$

$t= \frac{-80\pm \sqrt{6400+19200}}{-32}$

$t= \frac{-80\pm \sqrt{25600}}{-32}$

Simplify:

$t = -\frac{5}{2}$ = -2.5 sec and $t = \frac{15}{2}$ = 7.5 sec

Time can't be in negative;

therefore, the time it took the object to hit the ground is 7.5 sec

8 0

3 years ago

What is the rational number equivalent to __ 3.24?

guajiro [1.7K]

Answer:

$\frac{324}{100}$

Step-by-step explanation:

Think of a rational number as a fraction. The definition of a rational number is that it is the ratio of integers that, when divided, is either an integer, a decimal that terminates, or a decimal that repeats. 6/3 = 2 (6/3 is a rational number that divides to 2); 1/2 = .5 (1/2 is a rational number that divides to .5 which is a terminating decimal, meaning it ends); 1/3 = .33333333 (1/3 is a rational number that divides to .3333333 which is a repeating decimal). If we want to express 3.24 as a rational number, let's first put it into fraction form. The 4 in .24 is in the hundredths place, so as a fraction, .24 is 24/100. Check this on your calculator. Divide 24 by 100 and you get .24. So now what we have is $3\frac{24}{100}$

Now express that mixed fraction as an improper and you're done. 3 times 100 is 300; 300 + 24 = 324. Put that back over 100 and your rational number is 324/100. Check that on your calculator, as well, just to see that it's true.

5 0

3 years ago

Y 45° 30° N 17 I need help pls

melisa1 [442]

Answer:

x=29.4

Step-by-step explanation:

To help find the sides of a triangle, I use SOHCAHTOA.

SOH - CAH - TOA

S=O/H ( $Sine=\frac{opposite}{hypotenuse}$ )

C=A/H ( $Cosine=\frac{adjacent}{hypotenuse}$ )

T=O/A ( $Tangent =\frac{opposite}{adjacent}$ )

Let's find x first. We know 2 parts of the triangle: the adjacent leg, and the angle that is opposite of that.

So it would be tangent (tan).

opposite = 17

adjacent = 30°

Plug these numbers into the calculator and you should get your answer.

$\frac{17}{tan(30)} = 29.44486372...$

x=29.4

Try to do y on your own and let me know if you have any questions!

Also correct me if I'm wrong on anything.

Hope this information helps!

4 0

2 years ago

The expression 3xy+12y-5x+7w has how many terms in polynomial ??

bulgar [2K]

Answer:

Step-by-step explanation:

8 0

2 years ago

Read 2 more answers

Tell whether each graph is a function and justify your answer. Which graph is not a good representation of a real-world situati

mina [271]

Using the function concept, it is found that:

Graph B is a function because each value of x corresponds to exactly one y-value.

In a function, one value of the input can be related to only one value of the output.

In a graph, it means that for each value of x(horizontal axis), there can be only one respective value of y(vertical axis).

In this problem, at Graph A, when x = 5, for example a vertical line crosses the function 3 times, hence there are 3 respective values of y for x = 5, and the same is valid for other values of x, hence it is not a function.

At Graph B, for each value of x, there is only one value of y, hence it is a function.

Hence:

Graph B is a function because each value of x corresponds to exactly one y-value.

To learn more about the function concept, you can take a look at brainly.com/question/12463448

5 0

2 years ago