How many square inches of cloth are cut from the square? (π = 3.14)

How do you find the original price after a discount. The sales price is 55.50 and the percent of discount is 75%.

Arte-miy333 [17]

Well first we know that 55.50 is 25% so I guess multiply it by 3 to get the full price equalling nearly 166 which is closest to 165, so that’d be my answer. Sorry if wrong.

6 0

3 years ago

Read 2 more answers

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

Additive inverse of −2, additive identity of −5, additive inverse of 3, multiplicative identity of 19, and multiplicative invers

monitta

Answer:

See Explanation

Step-by-step explanation:

a) Additive inverse of −2

the additive inverse of a number a is the number that, when added to 'a', yields zero. This number is also known as the opposite (number), sign change, and negation.
So the Additive inverse of -2 is 2. ∴ -2+2=0

b) Additive identity of −5

Additive identity is the value when added to a number, results in the original number. When we add 0 to any real number, we get the same real number.
-5 + 0 = -5. Therefore, 0 is the additive identity of any real number.

c) additive inverse of 3

Two numbers are additive inverses if they add to give a sum of zero. 3 and -3 are additive inverses since 3 + (-3) = 0. -3 is the additive inverse of 3.

d). multiplicative identity of 19

an identity element (such as 1 in the group of rational numbers without 0) that in a given mathematical system leaves unchanged any element by which it is multiplied
Multiplicative identity if 19 is 1 only, since 19 x 1 = 19.

e) multiplicative inverse of 7

Dividing by a number is equivalent to multiplying by the reciprocal of the number. Thus, 7 ÷7=7 × 1⁄7 =1. Here, 1⁄7 is called the multiplicative inverse of 7.

d) | 11-5|×|1-5|

| 11-5|×|1-5| ⇒ I6I×I-4I ⇒ 6×4 ⇒ 24

8 0

3 years ago

What is the degree of the equation?

Kisachek [45]

Answer:

Degree: x= -1, $\frac{8}{5}$

leading coefficient: 5

Step-by-step explanation:

hope this helps!!!

5 0

3 years ago

1. What is the solution to this equation?<br> 2 x + 10 = 28

Colt1911 [192]

Answer:

9

Step-by-step explanation:

2x=28-10

2x=18

x=18÷2

x=9

3 0

3 years ago

Read 2 more answers