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3 years ago

Using the quadratic formula to solve x? + 20 = 2x, what are the values of x?

1 answer:

6 0

I am not sure if the “+” was supposed to go there or if that was just a typo, so I do apologize if this is wrong... but if it doesn’t belong in the equation at all, 20 = 2X is a fairly simply multiplication problem. You are to divide both sides by the 2 and you should get X = 10, because 2 goes into 20, 10 times; and the 2 goes into 2 only once, therefore the 2 now gets cancelled out.

Answer: 20 divided by 2 = 2x divided by 2 is now 10 = X.

Really hope this helps you, have a good day :)

You might be interested in

find the column which has products that are the sum of the yellow shaded numbers in each row Shaded the column what pattern do y

BaLLatris [955]

Answer:

They are even numbers (divisible by two)

Step-by-step explanation:

The number column starts from 2 and is incremented by two for every number in the column. The remainder of the division of each number in the sequence is zero and the result of the division is sequence 1,2,3,4,5,6,7...

Therefore, the numbers in the column are even numbers.

6 0

3 years ago

A rock thrown vertically upward from the surface of the moon at a velocity of 36m/sec reaches a height of s = 36t - 0.8 t^2 met

Verdich [7]

Answer:

a. The rock's velocity is $v(t)=36-1.6t \:{(m/s)}$ and the acceleration is $a(t)=-1.6 \:{(m/s^2)}$

b. It takes 22.5 seconds to reach the highest point.

c. The rock goes up to 405 m.

d. It reach half its maximum height when time is 6.59 s or 38.41 s.

e. The rock is aloft for 45 seconds.

Step-by-step explanation:

Velocity is defined as the rate of change of position or the rate of displacement. $v(t)=\frac{ds}{dt}$
Acceleration is defined as the rate of change of velocity. $a(t)=\frac{dv}{dt}$

The rock's velocity is the derivative of the height function $s(t) = 36t - 0.8 t^2$

$v(t)=\frac{d}{dt}(36t - 0.8 t^2) \\\\\mathrm{Apply\:the\:Sum/Difference\:Rule}:\quad \left(f\pm g\right)'=f\:'\pm g'\\\\v(t)=\frac{d}{dt}\left(36t\right)-\frac{d}{dt}\left(0.8t^2\right)\\\\v(t)=36-1.6t$

The rock's acceleration is the derivative of the velocity function $v(t)=36-1.6t$

$a(t)=\frac{d}{dt}(36-1.6t)\\\\a(t)=-1.6$

b. The rock will reach its highest point when the velocity becomes zero.

$v(t)=36-1.6t=0\\36\cdot \:10-1.6t\cdot \:10=0\cdot \:10\\360-16t=0\\360-16t-360=0-360\\-16t=-360\\t=\frac{45}{2}=22.5$

It takes 22.5 seconds to reach the highest point.

c. The rock reach its highest point when t = 22.5 s

Thus

$s(22.5) = 36(22.5) - 0.8 (22.5)^2\\s(22.5) =405$

So the rock goes up to 405 m.

d. The maximum height is 405 m. So the half of its maximum height = $\frac{405}{2} =202.5 \:m$

To find the time it reach half its maximum height, we need to solve

$36t - 0.8 t^2=202.5\\36t\cdot \:10-0.8t^2\cdot \:10=202.5\cdot \:10\\360t-8t^2=2025\\360t-8t^2-2025=2025-2025\\-8t^2+360t-2025=0$

For a quadratic equation of the form $ax^2+bx+c=0$ the solutions are

$x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$\mathrm{For\:}\quad a=-8,\:b=360,\:c=-2025:\\\\t=\frac{-360+\sqrt{360^2-4\left(-8\right)\left(-2025\right)}}{2\left(-8\right)}=\frac{45\left(2-\sqrt{2}\right)}{4}\approx 6.59\\\\t=\frac{-360-\sqrt{360^2-4\left(-8\right)\left(-2025\right)}}{2\left(-8\right)}=\frac{45\left(2+\sqrt{2}\right)}{4}\approx 38.41$

It reach half its maximum height when time is 6.59 s or 38.41 s.

e. It is aloft until s(t) = 0 again

$36t - 0.8 t^2=0\\\\\mathrm{Factor\:}36t-0.8t^2\rightarrow -t\left(0.8t-36\right)\\\\\mathrm{The\:solutions\:to\:the\:quadratic\:equation\:are:}\\\\t=0,\:t=45$

The rock is aloft for 45 seconds.

5 0

3 years ago

Write an algebraic expression of the verbal expression the quotien of five times x and fifteen

faust18 [17]

5x+ (5)15

or

5(x+15)

I hope this helps

4 0

3 years ago

2x+2y=10 solve for x

irakobra [83]

Isolate the x. Note the equal sign. What you do to one side you do to the other.

Subtract 2y from both sides

2x + 2y (-2y) = 10 (-2y)

2x = 10 - 2y

Isolate the x, divide 2 from both sides and from all terms.

(2x)/2 = (10 - 2y)/2

x = 5 - y

Place the variable in the front

x = -y + 5

x = -y + 5 is your answer

hope this helps

7 0

3 years ago

A tank pumps out liquid at a rate of 12 gallons every 20 days. What is the unit rate in gallons per week?

pashok25 [27]

Answer:

4.2

Step-by-step explanation:

simplify 12 and 20 to 6 and 10 then divide 6 by 10 and multiply by 7 to get the answer.

8 0

3 years ago