All categories

3 years ago

15 more than three times a number is equal to 75 Also please do a step by step

Mathematics

1 answer:

Vlad [161]3 years ago

4 0

Answer:

Step-by-step explanation:

3n+15=75

three times a number is 3n. +15 is 15 more.

3n+15=75 subtract 15 from both sides to get the 3n alone

3n=60 divide by 3 to get the n by itself

n=20

You might be interested in

Consider this quadratic equation. 2x2 − 1 = 3x + 4 Which equation correctly applies the quadratic formula?

Mariulka [41]

Answer:

$\frac{-(-3)+-\sqrt{(-3)^2-4(2)(-5)}}{2(2)}$

Step-by-step explanation:

Quadratic formula: $\frac{-b+-\sqrt{b^2-4ac} }{2a}$

$2x^2-1=3x+4\\\\2x^2-3x-5=0\\\\\\frac{-(-3)+-\sqrt{(-3)^2-4(2)(-5)}}{2(2)} \\\frac{3+-\sqrt{9+40} }{4}$

$x = \frac{3+-7}{4}$

Hope this helps and God bless!

6 0

3 years ago

Factor the expression 7x^2 + 50x + 7 (Type your answer in factored form.)

alina1380 [7]

Answer: (7x + 1)(x + 7)

Step-by-step explanation:

$Factor the following:$$7 x^{2}+50 x+7$$Factor the quadratic $7 x^{2}+50 x+7$. The coefficient of $x^{2}$ is 7 and the constant term is 7. The product of 7 and 7 is 49 . The factors of 49 which sum to 50 are 1 and 49. So:\\\\ $7 x^{2}+50 x+7\\=7 x^{2}+49 x+x+7\\=7(7 x+1)+x(7 x+1)$ \\\\Factor $7 x+1$ from $7(7 x+1)+x(7 x+1)$ :$$\\\\Answer:(7 x+1)(x+7)$

3 0

3 years ago

Read 2 more answers

Simplify:

Nesterboy [21]

Answer:

Step-by-step explanation:

$\sqrt{3}$ times $\sqrt{3}$ = 3 and $\sqrt{3}$ times x = $\sqrt{3}$ x

So that means that answer is 3+ $\sqrt{3}$ x which is C

3 0

3 years ago

Determine the period.

Ugo [173]

Answer:

ima say around 180

Step-by-step explanation:

3 0

3 years ago

A biologist is studying the growth of a particular species of algae. She writes the fall inclusion to show the radius of the alg

horrorfan [7]

Answer:

Part A)

A reasonable domain to plot the growth function is:

$0\leq d \leq 12$

Part B)

The y-intercept represents that when the biologist started her study, the radius of the algae was five millimeters.

Part C)

The average rate of change from d = 4 to d = 11 was about 0.11. This means that from the 4th day to the 11th, the radius of the algae grew, on average, at a rate of 0.11 mm per day.

Step-by-step explanation:

The radius of the algae f(d) in millimeters after d days is given by the function:

$f(d)=5(1.02)^d$

Part A)

We know that the radius of the algae was approximately 6.34 mm when the biologist concluded her study. To find the reasonable domain, we can substitute 6.34 for f(d) and solve for d. Therefore:

$6.34=5(1.02)^d$

Divide both sides by five:

$(1.02)^d=1.268$

Take the log of both sides with base 1.02:

$\displaystyle d=\log_{1.02}1.268$

Using the Change of Base Property, evaluate for d:

$\displaystyle d=\frac{\log 1.268}{\log 1.02}=11.9903...\approx 12$

So, the biologist concluded her study after 12 days.

Therefore, a reasonable domain to plot the growth function is:

$0\leq d\leq 12$

Part 2)

The y-intercept of the function is when d = 0. Find the y-intercept:

$f(0)=5(1.02)^{(0)}=5(1)=5$

Since d represent the amount of days after the study had begun, the y-intercept represents the radius of the algae on the initial day.

So, when the biologist started her study, the radius of the algae was five millimeters.

Part 3)

To find the average rate of change for a nonlinear function, we find the slope between the two endpoints on the interval.

We want to find the average rate of change of f(d) from d = 4 to d = 11.

Find the endpoints:

$f(4)=5.4121...\text{ and } f(11)=6.2168...$

And find the slope between them:

$\displaystyle m=\frac{f(11)-f(4)}{11-4}=0.1149...\approx 0.11$

Since f(d) measures millimeters and d measures days, this tells us that, on average, the radius of the algae grew by about 0.11 mm per day from the 4th day to the 11th day.

5 0

3 years ago