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3 years ago

Which expression is equivalent to 4 times the sum of 3 and x

Mathematics

1 answer:

vovikov84 [41]3 years ago

8 0

Answer:

4(3+x)

Step-by-step explanation:

If any thing is in the brackets you need to do it first

so if you do 3 + x × 4 it will give yo 4x + 3 or 3 +4x

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What you do with value of expressions

svp [43]

You express the values in which the teacher or tutor or whatever assigned you.

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2 years ago

Describe a sequence of transformations that maps triangle ABC onto triangle A"B"C"<br> Help please?

monitta

the answer is reflection

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3 years ago

Is negative 5/8ths more than,less than or equal to 0.27?

ollegr [7]

It is less than. Any negative number compared to a positive number will be less than.

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3 years ago

The students in Mr. Wilson's Physics class are making golf ball catapults. The

Mnenie [13.5K]

Answer:

Part a) About 48.6 feet

Part b) About 8.3 feet

Part c) The domain is $0 \leq x \leq 48.6\ ft$ and the range is $0 \leq y \leq 8.3\ ft$

Step-by-step explanation:

we have

$y=-0.014x^{2} +0.68x$

This is a vertical parabola open downward (the leading coefficient is negative)

The vertex represent a maximum

where

x is the ball's distance from the catapult in feet

y is the flight of the balls in feet

Part a) How far did the ball fly?

Find the x-intercepts or the roots of the quadratic equation

Remember that

The x-intercept is the value of x when the value of y is equal to zero

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$-0.014x^{2} +0.68x=0$

$a=-0.014\\b=0.68\\c=0$

substitute in the formula

$x=\frac{-0.68(+/-)\sqrt{0.68^{2}-4(-0.014)(0)}} {2(-0.014)}$

$x=\frac{-0.68(+/-)0.68} {(-0.028)}$

$x=\frac{-0.68(+)0.68} {(-0.028)}=0$

$x=\frac{-0.68(-)0.68} {(-0.028)}=48.6\ ft$

therefore

The ball flew about 48.6 feet

Part b) How high above the ground did the ball fly?

Find the maximum (vertex)

$y=-0.014x^{2} +0.68x$

Find out the derivative and equate to zero

$0=-0.028x +0.68$

Solve for x

$0.028x=0.68$

$x=24.3$

<em>Alternative method</em>

To determine the x-coordinate of the vertex, find out the midpoint between the x-intercepts

$x=(0+48.6)/2=24.3\ ft$

To determine the y-coordinate of the vertex substitute the value of x in the quadratic equation and solve for y

$y=-0.014(24.3)^{2} +0.68(24.3)$

$y=8.3\ ft$

the vertex is the point (24.3,8.3)

therefore

The ball flew above the ground about 8.3 feet

Part c) What is a reasonable domain and range for this function?

we know that

A reasonable domain is the distance between the two x-intercepts

$0 \leq x \leq 48.6\ ft$

All real numbers greater than or equal to 0 feet and less than or equal to 48.6 feet

A reasonable range is all real numbers greater than or equal to zero and less than or equal to the y-coordinate of the vertex

we have the interval -----> [0,8.3]

$0 \leq y \leq 8.3\ ft$

All real numbers greater than or equal to 0 feet and less than or equal to 8.3 feet

8 0

2 years ago

How is the sum expressed in sigma notation? <br> 1/64+1/16+1/4 + 1 + 4

shusha [124]

9514 1404 393

Answer:

sum = ∑[n=1,5] 4^(n-4)

Step-by-step explanation:

First of all, you need to be able to describe the n-th term.

Here, we have ...

term #: 1, 2, 3, 4, 5

value: 4^-3, 4^-2, 4^-1, 4^0, 4^1

That is, the exponent of 4 is 4 less than the term number. So, the n-th term is 4^(n-4). The sum of the 5 terms shown is then ...

$\displaystyle sum=\sum_{n=1}^5{4^{n-4}}$

5 0

2 years ago