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3 years ago

How do you simply 3x-7+9-2x=x+2

Mathematics

1 answer:

Gre4nikov [31]3 years ago

7 0

Answer:

x+2=x+2

Step-by-step explanation:

Combine like terms

3x+(-2x) and (-7)+9

x+2=x+2

You might be interested in

4 + 6^2 + 9 ∙ 3 - 10

Korvikt [17]

4+6^2+9•3-10

PEMDAS
P=parentheses
E=exponent
m=multiplication
d=division
a=addition
s=subtraction

*no parentheses in this equation
*exponent = 6^2
6^2=36
4+36+9•3-10
*multiplication = 9•3
9•3=27
4+36+27-10
*addition=4+36+27
4+36+27=67
67-10
*subtraction=67-10
67=10=57

ANSWER=57

please give brainliest itd mean a lot<3

3 0

3 years ago

An object is heated to 100°. It is left to cool in a room that

stepladder [879]

Answer:

Step-by-step explanation:

Use Newton's Law of Cooling for this one. It involves natural logs and being able to solve equations that require natural logs. The formula is as follows:

$T(t)=T_{1}+(T_{0}-T_{1})e^{kt}$ where

T(t) is the temp at time t

T₁ is the enviornmental temp

T₀ is the initial temp

k is the cooling constant which is different for everything, and

t is the time (here, it's in minutes)

If we are looking first for the temp after 20 minutes, we have to solve for the k value. That's what we will do first, given the info that we have:

T(t) = 80

T₁ = 30

T₀ = 100

t = 5

k = ?

Filling in to solve for k:

$80=30+(100-30)e^{5k}$ which simplifies to

$50=70e^{5k}$ Divide both sides by 70 to get

$\frac{50}{70}=e^{5k}$ and take the natural log of both sides:

$ln(\frac{5}{7})=ln(e^{5k})$

Since you're learning logs, I'm assuming that you know that a natural log and Euler's number, e, "undo" each other (just like taking the square root of something squared). That gives us:

$-.3364722366=5k$

Divide both sides by 5 to get that

k = -.0672944473

Now that we have a value for k, we can sub that in to solve for T(20):

$T(20)=30+(100-30)e^{-.0672944473(20)}$ which simplifies to

$T(20)=30+70e^{-1.345888946}$

On your calculator, raise e to that power and multiply that number by 70:

T(20)= 30 + 70(.260308205) and

T(20) = 30 + 18.22157435 so

T(20) = 48.2°

Now we can use that k value to find out when (time) the temp of the object cools to 35°:

T(t) = 35

T₁ = 30

T₀ = 100

k = -.0672944473

t = ?

$35=30+100-30)e^{-.0672944473t}$ which simplifies to

$5=70e^{-.0672944473t}$

Now divide both sides by 70 and take the natural log of both sides:

$ln(\frac{5}{70})=ln(e^{-.0672944473t})$ which simplifies to

-2.63905733 = -.0672944473t

Divide to get

t = 39.2 minutes

3 0

3 years ago

Pls answer precisely

Nata [24]

Answer:

The third one

Step-by-step explanation:

Its asking if its positive in the interval [-3, -2]

Which means you only look at the graph from -3, -2 on the x axis and we are looking see which one is positive in that space. And by positive it means going up in a positive direction. Only the third one does this.

3 0

3 years ago

The sum of Sally and Beth's age is 60. Six years ago, Sally was 3 times as old as Beth. What are their present ages?

Thepotemich [5.8K]

Sally is 45 and Beth is 15.

45 + 15 = 60

15*3 = 45

4 0

3 years ago

Read 2 more answers

If $x$, $y$, and $z$ are positive integers such that $6xyz+30xy+21xz+2yz+105x+10y+7z=812$, find $x+y+z$.

harina [27]

Answer:

Step-by-step explanation:

When we simplify we get $z(6xy+21x+2y+7)+30xy+105x+10y=812.$

Then we continue to factor to get: $(z+5)(6xy+21x+2y+7)&=847.$

We then see that we can factor $(6xy+21x+2y+7)$ into $(z+5)(3x+1)(2y+7)&=847.$

we then do the prime factorization of 847, which i think is, $7*11*11$ . we have to find the numbers that multiply to 847 and then plug them into z+5, 3x=1,2y+7.

It has to be a positive, non-negative integer, right?

We also see that 3x+1=11 so we see that x=10/3 (which wont work).

So 3x+1=7, so x=2.

So 11 has to be in another term. It has to be in 2y+7=11 so y=2

for the last term we get z+5=11 so z=6

2+2+6=10

Hope this helps and if you want please consider giving me brainliest. :)

8 0

3 years ago