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3 years ago

Solve by factoring or finding square roots x^2-6x-7=0

Mathematics

2 answers:

uysha [10]3 years ago

7 0

Answer:

Step-by-step explanation:

$x^2-6x-7=0\\\\x^2+x-7x-7=0\\\\x(x+1)-7(x+1)=0\\\\(x+1)(x-7)=0\iff x+1=0\ \vee\ x-7=0\\\\x+1=0\qquad\text{subtract 1 from both sides}\\\bold{x=-1}\\\\x-7=0\qquad\text{add 7 to both sides}\\\bold{x=7}$

Nata [24]3 years ago

7 0

Answer:

x = - 1, x = 7

Step-by-step explanation:

Given

x² - 6x - 7 = 0

Consider the factors of the constant term (- 7 ) which sum to give the coefficient of the x- term

The factors are - 7 and + 1, since

- 7 × 1 = - 7 and - 7 + 1 = - 6, hence

(x - 7)(x + 1) = 0

Equate each factor to zero and solve for x

x - 7 = 0 ⇒ x = 7

x + 1 = 0 ⇒ x = - 1

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A baseball is dropped from a glider 500 feet above the ground. The height (in feet) above the ground is modeled by the function

Sophie [7]

A) 436 ft

B) t = 5 sec

C) 5.60 s

Step-by-step explanation:

The height of the ball at time t is given by the equation

$h(t)=-16t^2+500$

where

$-16 ft/s^2$ is the acceleration of the ball (acceleration of gravity, downward)

+500 is the initial height of the ball, at time t = 0

Here we want to find the height of the ball after 2 seconds, so at a time of

t = 2 s

Substituting into the equation, we find:

$h(2)=-16\cdot 2^2+500=436 ft$

Here we want to find the time it takes for the ball to fall to a height of 100 feet above the ground, so the time t at which

h(t) = 100 ft

As stated in the text of the question, the height of the ball at time t is given by

$h(t)=-16t^2+500$

Since

h(t) = 100, we have

$100=-16t^2+500$

And solving for t we find:

$16t^2=400\\t^2=25\\t=\pm 5$

So, the correct solution is the positive one:

t = 5 sec

The ball reaches the ground when the height of the ball has became zero:

$h(t) = 0$

The height of the ball at time t is given by

$h(t)=-16t^2+500$

And substituting

h(t) = 0

We get

$0=-16t^2+500$

And solving the equation for t, we find the time t at which the ball reaches the ground:

$16t^2=500\\t^2=31.25\\t=\pm 5.6 s$

So, the correct solution is the positive one:

t = 5.60 s

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4 years ago

You start 80 miles east of pittsburgh and drive east at a constant speed of 65 miles per hour. (assume that the road is straight

Masja [62]

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3 years ago

Find the mode for the<br> following data set {1,3,5,7,9]<br><br> PLS HELP

kvasek [131]

Answer: There is no mode.

Step-by-step explanation:

The mode is the number in a data set that occurs most frequently. Count how many times each number occurs in the data set. The mode is the number with the highest tally. It's ok if there is more than one mode. And if all numbers occur the same number of times there is no mode.

Hope this helps!

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nirvana33 [79]

Answer:

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Step-by-step explanation:

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ollegr [7]

Answer:

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Step-by-step explanation:

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