Answer:
f(-3)= -3
Step-by-step explanation:
We are given the function:
f(x) = 2x+3
and asked to find f(-3). Essentially, we want to find f(x) when x is equal to -3.
Therefore, we can substitute -3 for each x in the function.
f(x)= 2x+3 at x= -3
f(-3)= 2(-3) +3
Solve according to PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition and Subtraction
Multiply 2 and -3.
f(-3) = (2*-3) +3
f(-3)= (-6)+3
Add -6 and 3.
f(-3)= (-6+3)
f(-3)= -3
If f(x)= 2x+3, then<em> f(-3)= -3</em>
Answer:
A sample of 179 is needed.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.44.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
A previous study found that for an average family the variance is 1.69 gallon?
This means that 
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So






Rounding up
A sample of 179 is needed.
Answer:


Step-by-step explanation:
<u>Equation Solving</u>
We are given the equation:
![\displaystyle x=\sqrt[3]{\frac{3y+16}{2y+9}}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B3y%2B16%7D%7B2y%2B9%7D%7D)
i)
To make y as a subject, we need to isolate y, that is, leaving it alone in the left side of the equation, and an expression with no y's to the right side.
We have to make it in steps like follows.
Cube both sides:
![\displaystyle x^3=\left(\sqrt[3]{\frac{3y+16}{2y+9}}\right)^3](https://tex.z-dn.net/?f=%5Cdisplaystyle%20x%5E3%3D%5Cleft%28%5Csqrt%5B3%5D%7B%5Cfrac%7B3y%2B16%7D%7B2y%2B9%7D%7D%5Cright%29%5E3)
Simplify the radical with the cube:

Multiply by 2y+9

Simplify:

Operate the parentheses:


Subtract 3y and
:

Factor y out of the left side:

Divide by
:

ii) To find y when x=2, substitute:





Answer:
1 and -4
Step-by-step explanation:
cause when you factor the equation its (x-1)(x+4)
Answer:
Approximate solution is 541.
Step-by-step explanation:
y' = 2xy, Δx = 0.4.
Make a table:
x y y' y' Δx + y
1 2 4 4*0.4 + 2 = 3.6 <---this is the new y value.
1.4 3.6 10.08 7.632
1.8 7.632 27.48 18.624
2.2 18.624 81.95 51.70
2.6 51.70 268.85 159.24
3 159.24 955.44 541.4