Garrrrryy no need to show work two questions thankks

Mathematics

1 answer:

irakobra [83]4 years ago

8 0

1. $x^2-x-72=0$
$\Delta=(-1)^2-4*1*(-72)=1+288=289$
$\sqrt{\Delta}=17$
$x_1=\frac{1-17}{2}=-8$
$x_2=\frac{1+17}{2}=9$

2. $f(x)=x^2+12x+20$
$\Delta=144-80=64$
$\sqrt{\Delta}=8$
$x_1=\frac{-12-8}{2}=-10$
$x_2=\frac{-12+8}{2}=-2$

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There are 47 students in a class and 35 of these students passed their Geometry test.

Dafna11 [192]

Answer:

74.47%

Step-by-step explanation:

Divide the total number of students by the number who passed

passed/total

35/47

0.74468085

As a percent:

0.74468085*100=74.4680851

Rounded to the nearest hundreth:

74.4680851

74.47%

So, 74.47% passed the geometry test

Hope this helps! :)

5 0

3 years ago

Alicia can row 6 miles downstream in the same time it takes her to row 4 miles upstream.She rows downstream miles/hour faster th

disa [49]

Answer:

Option D. 9 mi/hr downstream, 6 mi/hr upstream

Step-by-step explanation:

The complete question is

Alicia can row 6 miles downstream in the same time it takes her to row 4 miles upstream. She rows downstream 3 miles/hour faster than she rows upstream. Find Alicia’s rowing rate each way

Define the variables

Let

x -----> Alicia's rowing rate downstream in miles per hour

y ----> Alicia's rowing rate upstream in miles per hour

we know that

The rate is equal to the distance divided by the time

The time is equal to the distance divided by the rate

we have

$\frac{6}{x}=\frac{4}{y}$