Answer:
second option
Step-by-step explanation:
Given
f(x) = (x - 7)(x + 4)(3x - 2)
To find the zeros let f(x) = 0, that is
(x - 7)(x + 4)(3x - 2) = 0
Equate each factor to zero and solve for x
x - 7 = 0 ⇒ x = 7
x + 4 = 0 ⇒ x = - 4
3x - 2 = 0 ⇒ 3x = 2 ⇒ x = 
zeros are x = - 4, x = , x = 7
5x - 3y = -11 (×2)
2x - 6y = -14 (x5)
10x - 6y = -22
10x - 30y = -70
---------------------- -
24y = 48
y = 2
Let's to the first example:
f(x) = x^2 + 9x + 20
Ussing the formula of basckara
a = 1
b = 9
c = 20
Delta = b^2 - 4ac
Delta = 9^2 - 4.(1).(20)
Delta = 81 - 80
Delta = 1
x = [ -b +/- √(Delta) ]/2a
Replacing the data:
x = [ -9 +/- √1 ]/2
x' = (-9 -1)/2 <=> - 5
Or
x" = (-9+1)/2 <=> - 4
_______________
Already the second example:
f(x) = x^2 -4x -60
Ussing the formula of basckara again
a = 1
b = -4
c = -60
Delta = b^2 -4ac
Delta = (-4)^2 -4.(1).(-60)
Delta = 16 + 240
Delta = 256
Then, following:
x = [ -b +/- √(Delta)]/2a
Replacing the information
x = [ -(-4) +/- √256 ]/2
x = [ 4 +/- 16]/2
x' = (4-16)/2 <=> -6
Or
x" = (4+16)/2 <=> 10
______________
Now we are going to the 3 example
x^2 + 24 = 14x
Isolating 14x , but changing the sinal positive to negative
x^2 - 14x + 24 = 0
Now we can to apply the formula of basckara
a = 1
b = -14
c = 24
Delta = b^2 -4ac
Delta = (-14)^2 -4.(1).(24)
Delta = 196 - 96
Delta = 100
Then we stayed with:
x = [ -b +/- √Delta ]/2a
x = [ -(-14) +/- √100 ]/2
We wiil have two possibilities
x' = ( 14 -10)/2 <=> 2
Or
x" = (14 +10)/2 <=> 12
________________
To the last example will be the same thing.
f(x) = x^2 - x -72
a = 1
b = -1
c = -72
Delta = b^2 -4ac
Delta = (-1)^2 -4(1).(-72)
Delta = 1 + 288
Delta = 289
Then we are going to stay:
x = [ -b +/- √Delta]/2a
x = [ -(-1) +/- √289]/2
x = ( 1 +/- 17)/2
We will have two roots
That's :
x = (1 - 17)/2 <=> -8
Or
x = (1+17)/2 <=> 9
Well, this would be your answers.
Answer:
Step-by-step explanation:
Givens
d1 = d
d2 = 75 - d
r1 = x
r2 = x + 7
t = 3
Equation
x*t + (x + 7)*t = 75
This equation represents the total distance travelled. Neither one of the cyclists have gone 75 miles, but they both have gone distances that equal a total of 75 miles.
Solution
3x + (x + 7)*3 = 75
3x + 3x + 21 = 75
6x + 21 = 75
6x = 54
6x/6 = 54/6
x = 9
Answer
The first cyclist is going 9 miles / hr
The second cyclist is going 16 miles / hour
Answer:
Step-by-step explanation:
radius=diameter/2
13/2
6.5
circumference of a circle=2πr
=2*3.14*6.5
=40.82 feet
=
