All categories

3 years ago

What is x in -2/3x - 11 = -7

Mathematics

1 answer:

mafiozo [28]3 years ago

7 0

-2/3x -11=-7
-2/3x = 11 - 7

-2/3x = 4

x = 4 : (-2/3)

x = 4 * (-3/2)

x = 4 *(-3) : 2

x = -12 : 2

x = -6

You might be interested in

The digit in the hundreds place is the best stem value for the set of data

lisov135 [29]

Answer:

false, we loose to much insight,it's in the tens I guess, good trade off between smoothing and insight

8 0

2 years ago

4.2a - 3.5b - (1.8a + 2.7b - 1.9)

anygoal [31]

-0.7916666667 + 2.583333333b =<span>1.7916666663</span>

4 0

3 years ago

Newton's law of cooling states that the temperature of an object changes at a rate proportional to the difference between its te

Aleonysh [2.5K]

Answer:

t=5.18 minute

Step-by-step explanation:

Using Newton's law of cooling

$\frac{dT}{dt}=-k(T-T_{s})$

T is temperature of a cup of coffee at any time t $T_{s}$ , is the temperature of the surrounding and k is a constant of proportionality in this negative because temperature is decreasing.

$T(0)=190\\T(1)=170\\T_{s}=66$

$\frac{dT}{dt}=-k(T-T_{s})\\\frac{dT}{(T-T_{s})}=-k*dt\\\int\limits {\frac{1}{T-T_{s} } } \, dT=-\int\limits {k} \, dt\\ln(T-T_{s})=k*t+C\\e*ln(T-T_{s})=e^{k*t+C} \\T-T_{s}=e^{k*t}*e^{C}\\e^{C}=C\\T-T_{s}=e^{k*t}*C\\T=T_{s}+e^{k*t}*C$

To find constant knowing the time and the temperature the first step of the change of energy in cup of coffee

$T=T_{s} +e^{-k*t}*C\\ C=190-66=124\\170=66+124*e^{-k*2}\\ 170-66=124*e^{-k*2}\\ln(\frac{104}{124})=ln*e^{-k*2}\\-0.175=-k*2\\k=0.08794$

Now using the constant of decreasing can find the time to be a 145 temperature the cup of coffee

$145=66+124*e^{-k*t} \\145-66=124*^{-0.087*t}$

$ln(0.637)=ln*e(-0.087*t)\\-0.45=-0.087*t\\t=5.18minutes$

4 0

3 years ago

How do i cancel this app? -i was just charged $24 and do not have a subscription - what gives Brainly? How do I get my refund? L

ArbitrLikvidat [17]

Go to Settings > [Your Name] > iTunes & App Store.

Tap your Apple ID account and select View Apple ID.

Sign in with Face ID, Touch ID, or your Apple ID password.

Tap Subscriptions, then select an active subscription.

Tap Cancel Subscription

4 0

2 years ago

The width of a rectangular field is 20 feet less than its length. The area of the field is 12,000 ft? What is the length of the

Scilla [17]

Answer:

The answer is 120 feet.

Step-by-step explanation:

The area of the field (A) is:

A = w · l (w - width, l - length)

It is known:

A = 12,000 ft²

l = w - 20

So, let's replace this in the formula for the area of the field:

12,000 = w · (w - 20)

12,000 = w² - 20

⇒ w² - 20w - 12,000 = 0

This is quadratic equation. Based on the quadratic formula:

ax² + bx + c = 0 ⇒

In the equation w² - 20w - 12,000 = 0, a = 1, b = -20, c = -12000

Thus:

So, width w can be either

Since, the width cannot be a negative number, the width of the field is 120 feet.

6 0

2 years ago

Read 2 more answers