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3 years ago

A car travels 126 miles in 3 hours. At this rate, how many miles can the car travel in 4 hours?

Mathematics

1 answer:

almond37 [142]3 years ago

4 0

Answer:

Step-by-step explanation:

$\bold{METHOD\ 1:}\\\\\begin{array}{ccc}126\ mi&-&3h\\\\x\ mi&-&4h\end{array}\qquad\text{cross multiply}\\\\3x=(126)(4)\\3x=504\qquad\text{divide both sides by 3}\\x=168\ mi$

$\bold{METHOD\ 2:}\\\\126\ mi\ \text{in}\ 3\ h,\ \text{then}\ \dfrac{126\ mi}{3}=42\ mi\ \text{in}\ 1\ h.\\\\\text{If}\ 42\ mi\ \text{in}\ 1\ h,\ \text{then}\ (42\ mi)(4)=168\ mi\ \text{in}\ 4h.$

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Which is greater than or less than

poizon [28]

Answer:

C. -2/3 < -0.8

F. -3/5 < -0.35

Therefor, -2/3 is less than -0.8.

And, -3/5 is also less than -0.35.

Also, you could turn the fractions into decimals to make your life easier for example, -3/5 into decimal form is -0.6.

And -2/3 into decimal form is -0.6666

* Hopefully this helps:) Mark me the brainliest:)!!

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4 years ago

g Use this to find the equation of the tangent line to the parabola y = 2 x 2 − 7 x + 6 at the point ( 4 , 10 ) . The equation o

natali 33 [55]

Answer:

The tangent line to the given curve at the given point is $y=9x-26$ .

Step-by-step explanation:

To find the slope of the tangent line we to compute the derivative of $y=2x^2-7x+6$ and then evaluate it for $x=4$ .

$(y=2x^2-7x+6)'$ Differentiate the equation.

$(y)'=(2x^2-7x+6)'$ Differentiate both sides.

$y'=(2x^2)'-(7x)'+(6)'$ Sum/Difference rule applied: $(f(x)\pmg(x))'=f'(x)\pm g'(x)$

$y'=2(x^2)'-7(x)'+(6)'$ Constant multiple rule applied: $(cf)'=c(f)'$

$y'2(2x)-7(1)+(6)'$ Applied power rule: $(x^n)'=nx^{n-1}$

$y'=4x-7+0$ Simplifying and apply constant rule: $(c)'=0$

$y'=4x-7$ Simplify.

Evaluate y' for x=4:

$y'=4(4)-7$

$y'=16-7$

$y'=9$ is the slope of the tangent line.

Point slope form of a line is:

$y-y_1=m(x-x_1)$

where $m$ is the slope and $(x_1,y_1)$ is a point on the line.

Insert 9 for $m$ and (4,10) for $(x_1,y_1)$ :

$y-10=9(x-4)$

The intended form is $y=mx+b$ which means we are going need to distribute and solve for $y$ .

Distribute:

$y-10=9x-36$

Add 10 on both sides:

$y=9x-26$

The tangent line to the given curve at the given point is $y=9x-26$ .

------------Formal Definition of Derivative----------------

The following limit will give us the derivative of the function $f(x)=2x^2-7x+6$ at $x=4$ (the slope of the tangent line at $x=4$ ):

$\lim_{x \rightarrow 4}\frac{f(x)-f(4)}{x-4}$

$\lim_{x \rightarrow 4}\frac{2x^2-7x+6-10}{x-4}$ We are given f(4)=10.

$\lim_{x \rightarrow 4}\frac{2x^2-7x-4}{x-4}$

Let's see if we can factor the top so we can cancel a pair of common factors from top and bottom to get rid of the x-4 on bottom:

$2x^2-7x-4=(x-4)(2x+1)$

Let's check this with FOIL:

First: $x(2x)=2x^2$

Outer: $x(1)=x$

Inner: $(-4)(2x)=-8x$

Last: $-4(1)=-4$

---------------------------------Add!

$2x^2-7x-4$

So the numerator and the denominator do contain a common factor.

This means we have this so far in the simplifying of the above limit:

$\lim_{x \rightarrow 4}\frac{2x^2-7x-4}{x-4}$

$\lim_{x \rightarrow 4}\frac{(x-4)(2x+1)}{x-4}$

$\lim_{x \rightarrow 4}(2x+1)$

Now we get to replace x with 4 since we have no division by 0 to worry about:

2(4)+1=8+1=9.

6 0

4 years ago

4.) Aaron bought a new belt for school that was 30% off the regular price of $60. What was the

AURORKA [14]

A) 18

Apparently my answer has to be 20+ characters so this is filling space

6 0

3 years ago

Read 2 more answers

A bag has four green marbles, three red marbles, and three yellow marbles. What is the probability that you pick a yellow marble

valina [46]

Step-by-step explanation:

add all marbles together:

4 (green) + 3 (red) + 3 (yellow) = 10 marbles total

if we pick a yellow marble out of the bag and do not replace it, then we have 2 yellow marbles left.

we need to add marbles again with one yellow marble subtracted.

4 (green) + 3 (red) + 2 (yellow) =

new Total is 9 marbles.

so then we have 2 yellow marbles out of 9 total marbles.

2:9

or 2/9

or .22 (22%)

is the probability

6 0

3 years ago

Read 2 more answers

The circumference of a circular tabletop is 226. 08 inches. What is the area, in square inches, of the tabletop? *

Delicious77 [7]

Answer:

40,143.4 square inches

Step-by-step explanation:

c= 226.08

r= 113.04

area = Pi *r^2

3 0

2 years ago