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3 years ago

Determine the value of y, if x is 7. y = x2 - 1

Mathematics

2 answers:

Savatey [412]3 years ago

7 0

13 because if you plug in 7 y=7(2)-1 then do 7x2 and then it would be 14-1 so 13

ddd [48]3 years ago

4 0

Answer:

Step-by-step explanation:

If x is 7, then 7 * 2 = 13, and 14 - 1 = 13.

Hope that this helps!

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Find the square root of 24-16√2<br>

Minchanka [31]

Answer:

Step-by-step explanation:

The result can be shown in multiple forms.

Exact Form:

24 − 16 √ 2

Decimal Form:

1.37258300 …

7 0

3 years ago

A biologist has been observing a tree's height. This type of tree typically grows by 0.22 feet each month. Fifteen months into t

Lyrx [107]

Data:

x: number of months

y: tree's height

Tipical grow: 0.22

Fifteen months into the observation, the tree was 20.5 feet tall: x=15 y=20.5ft (15,20.5)

In this case the slope (m) or rate of change is the tipical grow.

m=0.22

To find the line's slope-intercep equation you use the slope (m) and the given values of x and y (15 , 20.5) in the next formula to find the y-intercept (b):

$\begin{gathered} y=mx+b \\ 20.5=0.22(15)+b \\ 20.5=3.3+b \\ 20.5-3.3=b \\ 17.2=b \end{gathered}$

Use the slope(m) and y-intercept (b) to write the equation:

$\begin{gathered} y=mx+b \\ \\ y=0.22x+17.2 \end{gathered}$ A) This line's slope-intercept equation is: y=0.22x+17.2

B) To find the height of the tree after 29 months you substitute in the equation the x for 29 and evaluate to find the y:

$\begin{gathered} y=0.22(29)+17.2 \\ y=6.38+17.2 \\ \\ y=23.58 \end{gathered}$ Then, after 29 months the tree would be 23.58 feet in height

C) In this case as you have the height and need to find the number of moths you substitute the y for 29.96feet and solve the equation for x, as follow:

$\begin{gathered} 29.96=0.22x+17.2 \\ 29.96-17.2=0.22x \\ 12.76=0.22x \\ \frac{12.76}{0.22}=x \\ \\ 58=x \end{gathered}$ Then, after 58 months the tree would be 29.96feet tall

3 0

1 year ago

Find the roots x^2-13x+30=0<br> (numbers only)

Morgarella [4.7K]

Answer:

Find the roots of x^2-13x+30=0 by solving for x

x= 10,3

Step-by-step explanation:

3 0

2 years ago

Question 8 Find the unit vector in the direction of (2,-3). Write your answer in component form. Do not approximate any numbers

slamgirl [31]

Answer:

The unit vector in component form is $\hat{u} = \left(\frac{2}{\sqrt{13} },-\frac{3}{\sqrt{13}} \right)$ or $\hat{u} = \frac{2}{\sqrt{13}}\,i-\frac{3}{13}\,j$ .

Step-by-step explanation:

Let be $\vec u = (2,-3)$ , its unit vector is determined by following expression:

$\hat {u} = \frac{\vec u}{\|\vec u \|}$

Where $\|\vec u \|$ is the norm of $\vec u$ , which is found by Pythagorean Theorem:

$\|\vec u\|=\sqrt{2^{2}+(-3)^{2}}$

$\|\vec u\| = \sqrt{13}$

Then, the unit vector is:

$\hat{u} = \frac{1}{\sqrt{13}} \cdot (2,-3)$

$\hat{u} = \left(\frac{2}{\sqrt{13} },-\frac{3}{\sqrt{13}} \right)$

The unit vector in component form is $\hat{u} = \left(\frac{2}{\sqrt{13} },-\frac{3}{\sqrt{13}} \right)$ or $\hat{u} = \frac{2}{\sqrt{13}}\,i-\frac{3}{13}\,j$ .

6 0

2 years ago

Anna made and sold x ceramic vases one week. Her profit, P, in dollars is calculated using the formula P = R - C . Where R repre

Alex73 [517]

Answer:

-0.5x² + 20x + 100

Step-by-step explanation:

Given:

R = 25x - 0.5x²

C = 100 + 5x

P = R - C

Where,

P = profits

R = Revenue

C = Cost

which expression represents her profit in dollars?

P = R - C

R = 25x - 0.5x²

C = 100 + 5x

= 25x - 0.5x² -(-100 + 5x )

= 25x - 0.5x² + 100 - 5x

= -0.5x² + 20x + 100

The expression which represents her profit in dollars is -0.5x² + 20x + 100

6 0

2 years ago