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3 years ago

John wants to create a line of dominoes 18 inches long with each domino spaced 1 1/2 in.apart.how many dominoes will he need

Mathematics

2 answers:

AysviL [449]3 years ago

7 0

Answer:

Step-by-step explanation:

if the line is 18 inches long and a 1.5 space apart then u divide them and 18 divided by 1.5 is 12

kherson [118]3 years ago

6 0

Answer:

Step-by-step explanation:

18/1.5=12

You might be interested in

The half-life of a radioactive substance is the time it takes for a quantity of the substance to decay to half of the initial am

posledela

Step-by-step walkthrough:

Well a standard half-life equation looks like this.

$N = N_0 * (\frac{1}{2})^{t/p$

$N_0$ is the starting amount of parent element.

$N$ is the end amount of parent element

$t$ is the time elapsed

$p$ is a half-life decay period

We know that the starting amount is 74g, and the period for a half-life is 2.8 days.

Therefore you can create a function based off of the original equation, just sub in the values you already know.

$N(t) = 74g * (\frac{1}{2})^{t/2.8days$

This is easy now that we have already made the function. Here we just reuse it, but plug in 2.8 days.

$N(t) = 74g * (\frac{1}{2})^{t/2.8days} = N(2.8days) = 74g * (\frac{1}{2})^{2.8days/2.8days}\\= 74g * \frac{1}{2} = 37g$

Now we just gotta do some algebra. Use the original function but this time, replace $N(t)$ with 10g and solve algebraically.

$10g = 74g * (\frac{1}{2})^{t/2.8days}\\\\\frac{10g}{74g} = (\frac{1}{2})^{t/2.8days}$

Take the log of both sides.

$log(\frac{5}{37}) = log((\frac{1}{2})^{t/2.8days})$

Use the exponent rule for log laws that, $log(b^x) = x*log(b)$

$log(\frac{5}{37}) = \frac{t}{2.8days} * log(\frac{1}{2})$

$\frac{log(\frac{5}{37})}{log(\frac{1}{2})} = \frac{t}{2.8days}$

$2.8 * \frac{log(\frac{5}{37})}{log(\frac{1}{2})} = t$

slap that in your calculator and you get

$t = 8.1 days$

7 0

2 years ago

Someone please help me on both the questions!!!

bonufazy [111]

Step-by-step explanation:

al nth term:

numerator:

$= {n}^{2}$

denominator:

$= n + 1$

so nth term :

$= \frac{ {n}^{2} }{n + 1}$

b). 1; 11; 27; 49

first difference: 10; 16; 22

second difference :6

formula for 1st difference:3a+b

formula for 2nd difference:2a

Therefore:

2a=6

a=3

3a+b=10

sub in a

3(3)+b=10

9+b=10

b=1

sub into quadratic formula

${an}^{2} + bn + c$

$(3) {(1)}^{2} + (1)(1) + c = 1$

$3(1) + 1 + c = 1$

$3 + 1 + c = 1$

$4 + c = 1$

$c = - 3$

So Tn:

$3 {n }^{2} + 1n - 3$

7 0

2 years ago

Read 2 more answers

Find the length of side xz give your answers to 3 significant figures

aleksandrvk [35]

Answer:

XZ ≈ 14.4 cm

Step-by-step explanation:

Using the cosine ratio in the right triangle

cos29° = $\frac{adjacent}{hypotenuse}$ = $\frac{ZY}{XZ}$ = $\frac{12.6}{XZ}$

Multiply both sides by XZ

XZ × cos29° = 12.6 ( divide both sides by cos29° )

XZ = $\frac{12.6}{cos29}$ ≈ 14. 4 ( to 3 sig. figs )

3 0

3 years ago

you have 4500 cubic centimeters of wax. how many cylindrical candles can you make from the wax if each candle is 15 cm tall and

ira [324]

Use the formula for the volume of a cylinder to work out how much wax you need to make one candle.

π×5²×15 = 375π

Then divide the amount of wax you have by the amount of wax you need to produce one candle to work out how many candles you can make.

4500 ÷ 375π = 3.82

However, you can't produce 82% of a candle, so you have to round down to 3 candles.

8 0

3 years ago

Find the equation for parabola<br> Focus(3,4)<br> Directrix y=2

sveta [45]

Answer:

Step-by-step explanation:

we know that distance d from the focus to P should be the same to the distance from P to the directrix

(x-h)^2=4p(y-k)

we need to find the y coordinate,

x is the same from focus, 3

y=(3, (4+2)/2)=(3,3)

we find p now by subtracting the y from the focus from the y that we just found

p=4-3=1

again (x-h)^2=4p(y-k), p=1

(x-3)^2=4(1)(y-3)

(x-3)^2=4(y-3), (x-3)^2=4y-12

simplify

4y=(x-3)^2+12

y=((x-3)^2)/4 + 3

4 0

3 years ago

Read 2 more answers