Jen factored x² - 4x - 21 as (x - 3)(x + 7) What did she do wrong?

2 answers:

6 0

Jen should have done (x+3)(x-7) bc the middle value of the original equation needs to be equal to the two numerical values added together from the factored equation

alexgriva [62]3 years ago

5 0

Answer:

She didn't put the sign's in the proper place, it should be ( x + 3 ) ( x - 7 )

Step-by-step explanation:

( x - 3 ) ( x + 7 ) = x² + 7x - 3x - 21 = x² + 4x - 21

( x + 3 ) ( x - 7 ) = x² - 7x + 3x - 21 = x² - 4x - 21

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A mule dear can 1/4 of a mile in 25 seconds. At this rate, what expression can be used to determine how fast a mule deer runs in

Naddika [18.5K]

We have to find how many seconds are in one hour.
There are 60 seconds in one minute, with 60 minutes in every hour.
60×60=3600
Now, see how many 25 seconds are in 3600 seconds.
3600÷25= 144
Now, we can multiply 144 by 14 or .25 since we are trying to find per hour.
144×.25= 36
36h
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5 0

3 years ago

Does anyone know how to do this (#2) PLZZZZ HELPPPPPPPP

timurjin [86]

Answer:

a.- slope= 36

Interpretation : The cable car travels 36 meter per minute

b.- y = 36x + 100

c.- 640 meters

Step-by-step explanation:

a.-

Find slope using the slope formula : $\frac{y2-y1}{x2-x1}$

Plug in the two given points: $\frac{1000-100}{25-0}$

Subtract the numbers : $\frac{900}{25}$

Reduce the fraction : 36

b.-

Using the given y-interspet (100) and the slope create an equation: y = 36x + 100

c.-

Using the equation you created plug in 15 for x to find the

distance: y = 36 (15) + 100

Multiply the numbers : y = 540 + 100

Add the numbers : y = 640

8 0

3 years ago

Alyssa takes part in the triathlon. She cycles 4/5 of the route, runs 7/8 of the route, and swims the rest of the way. She swims

hjlf

Answer:

12 miles

Step-by-step explanation:

Alyssa takes part in the triathlon. She cycles 4/5 of the route, runs 1/8 of the route, and swims the rest of the way. She swims 0.9 miles. Find the total distance of the triathlon route.

Total distance Alyssa cycled and ran =

$\frac{4}{5} + \frac{1}{8}$