All categories

2 years ago

N.) Evaluate the expression (xy)? + 8, when x = 2 and y = 4.

Mathematics

2 answers:

Marta_Voda [28]2 years ago

8 0

Answer:

Step-by-step explanation:

im guessing the ? has nothing to do with the equation but

xy is x*y or 2*4 (since the values of x & y were already given) not 24 which is sometimes a common mistake

2*4 is 8

and 8+8= 16 :)

any questions just ask me ♡

kodGreya [7K]2 years ago

4 0

Answer:

Step-by-step explanation:

x=2. y=4

following bodmas

2*4=8

8+8=16

You might be interested in

Solve by substitution<br><br> 8x+y=-16<br> -3x+ y= -5

azamat

Answer:

y=–8, x=–1

Step-by-step explanation:

I don't have time to explain

3 0

2 years ago

Initially 100 milligrams of a radioactive substance was present. After 6 hours the mass had decreased by 3%. If the rate of deca

Hitman42 [59]

Answer:

The half-life of the radioactive substance is 135.9 hours.

Step-by-step explanation:

The rate of decay is proportional to the amount of the substance present at time t

This means that the amount of the substance can be modeled by the following differential equation:

$\frac{dQ}{dt} = -rt$

Which has the following solution:

$Q(t) = Q(0)e^{-rt}$

In which Q(t) is the amount after t hours, Q(0) is the initial amount and r is the decay rate.

After 6 hours the mass had decreased by 3%.

This means that $Q(6) = (1-0.03)Q(0) = 0.97Q(0)$ . We use this to find r.

$Q(t) = Q(0)e^{-rt}$

$0.97Q(0) = Q(0)e^{-6r}$

$e^{-6r} = 0.97$

$\ln{e^{-6r}} = \ln{0.97}$

$-6r = \ln{0.97}$

$r = -\frac{\ln{0.97}}{6}$

$r = 0.0051$

$Q(t) = Q(0)e^{-0.0051t}$

Determine the half-life of the radioactive substance.

This is t for which Q(t) = 0.5Q(0). So

$Q(t) = Q(0)e^{-0.0051t}$

$0.5Q(0) = Q(0)e^{-0.0051t}$

$e^{-0.0051t} = 0.5$

$\ln{e^{-0.0051t}} = \ln{0.5}$

$-0.0051t = \ln{0.5}$

$t = -\frac{\ln{0.5}}{0.0051}$

$t = 135.9$

The half-life of the radioactive substance is 135.9 hours.

6 0

2 years ago

Technology required. A function f gives the number of stray cats in a town t years since

8090 [49]

This means that the number of stray cats in a town when the town started the animal control program is 729.

<h3>Exponential function</h3>

An exponential function is given by:

y = abˣ

Let y, x are variables, a is the initial value and b is the multiplication factor.

Where f is the number of stray cats in a town t years since the town started an animal control program.

Since $f(t) = 729(\frac{1}{3} )^t$

f(0) = 729(1/3)° = 729

This means that the number of stray cats in a town when the town started the animal control program is 729.

Find out more on Exponential function at: brainly.com/question/12940982

4 0

2 years ago

List two different ways Stuart could have created triangle A^ prime B^ prime C^ prime ' using a single transformation or a serie

AysviL [449]

Answer:

i don't know

Step-by-step explanation:

8 0

2 years ago

Karen has $800 to open a checking account. She wants an account with the lowest fees. She only writes about five checks per mont

Bogdan [553]

Answer:

The correct answer on e2020 is Account C

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers