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3 years ago

Please help due tmrw

Mathematics

2 answers:

shusha [124]3 years ago

5 0

Answer:

Step-by-step explanation:

less than equal to circle is filled

SashulF [63]3 years ago

5 0

Answer:

the answer that you are looking for would be A.

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Help!! 50 points and brainliest!

Viktor [21]

Answer:

Second choice:

$x=2t$

$y=4t^2+4t-3$

Fifth choice:

$x=t+1$

$y=t^2+4t$

Step-by-step explanation:

Let's look at choice 1.

$x=t+1$

$y=t^2+2t$

I'm going to subtract 1 on both sides for the first equation giving me $x-1=t$ . I will replace the $t$ in the second equation with this substitution from equation 1.

$y=(x-1)^2+2(x-1)$

Expand using the distributive property and the identity $(u+v)^2=u^2+2uv+v^2$ :

$y=(x^2-2x+1)+(2x-2)$

$y=x^2+(-2x+2x)+(1-2)$

$y=x^2+0+-1$

$y=x^2$

So this not the desired result.

Let's look at choice 2.

$x=2t$

$y=4t^2+4t-3$

Solve the first equation for $t$ by dividing both sides by 2:

$t=\frac{x}{2}$ .

Let's plug this into equation 2:

$y=4(\frac{x}{2})^2+4(\frac{x}{2})-3$

$y=4(\frac{x^2}{4})+2x-3$

$y=x^2+2x-3$

This is the desired result.

Choice 3:

$x=t-3$

$y=t^2+2t$

Solve the first equation for $t$ by adding 3 on both sides:

$x+3=t$ .

Plug into second equation:

$y=(x+3)^2+2(x+3)$

Expanding using the distributive property and the earlier identity mentioned to expand the binomial square:

$y=(x^2+6x+9)+(2x+6)$

$y=(x^2)+(6x+2x)+(9+6)$

$y=x^2+8x+15$

Not the desired result.

Choice 4:

$x=t^2$

$y=2t-3$

I'm going to solve the bottom equation for $t$ since I don't want to deal with square roots.

Add 3 on both sides:

$y+3=2t$

Divide both sides by 2:

$\frac{y+3}{2}=t$

Plug into equation 1:

$x=(\frac{y+3}{2})^2$

This is not the desired result because the $y$ variable will be squared now instead of the $x$ variable.

Choice 5:

$x=t+1$

$y=t^2+4t$

Solve the first equation for $t$ by subtracting 1 on both sides:

$x-1=t$ .

Plug into equation 2:

$y=(x-1)^2+4(x-1)$

Distribute and use the binomial square identity used earlier:

$y=(x^2-2x+1)+(4x-4)$

$y=(x^2)+(-2x+4x)+(1-4)$

$y=x^2+2x+-3$

$y=x^2+2x-3$ .

This is the desired result.

3 0

4 years ago

Read 2 more answers

Michael and Imani go out to eat for lunch.

Wittaler [7]

Part A= $27.32
Part B= $32.24

8 0

4 years ago

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How do you expand 2(x-5)^2+3 to get general form

svp [43]

The answers

2x^2-20x+53

8 0

3 years ago

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A 50-gal tank initially contains 20 gal of pure water. Salt- water solution containing 0.5 lb of salt for each gallon of water b

icang [17]

Answer:

x(15) = 21 lb

Step-by-step explanation:

Rate of change in volume of salt water solution = rate of volume incoming - rate of volume outgoing

dV/dt = 4 - 2 =2gal/min

So, the equation for volume at cetain time t at given conditions and values becomes,

V(t) = 2t + V

V(t) = 2t + 20 gal-------------------euqation (1)

Rate of change in amount of salt = rate of salt in - rate of salt out

dx/dt = {0.5*4} - {[x(t)/V(t)]*2}

dx/dt = 2-2[(x(t))/(2t+20)]

dx/dt = 2-[(x(t))/(v(t))] lb/min

Now, with integrating factor, we get

exp[∫(1/(1+10))dt)] = t+10

the equation becomes

(t + 10)*x' + x = 2*(t+10)

((t+10)*x') = 2*(t+10)

(t+10)*x = t² + 20t + C

As x(0) = 0,

x(t) = (t²+20t)/(t+10)

x(15) = (15²+20*15)/(15+10)

x(15) = 21 lb

4 0

3 years ago

Help me please asap!!!

Naya [18.7K]

Answer:

615.4³

Step-by-step explanation:

6 0

3 years ago

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