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
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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
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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
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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:
C
Step-by-step explanation:
Answer:
Step-by-step explanation:
I'll do them you arrange.
x + (x - 1) > 5
If you start with 3 you will see that the answer is that the left equals the right. So 4 is the smallest number x can have
3 + (3 - 1)>5
6 - 1 = 5 not something greater than 5
4 + (4 - 1) > 5
8 - 1 > 5
7 > 5 which is true.
Answer 4
5x - 3x > 9
2x > 9 x must equal 5
2*5 > 9
10 > 9
Answer 5
6x - 14 > 3 add 14 to both sides.
6x - 14+14>3+14
6x > 17 The answer to equality is just about 3. So three is the answer
6*3 > 17
18 > 17
Answer 3
2x - 1 > 0 Add 1 to both sides.
2x > 1 1 is the answer
2*1 > 1
2 > 1
Answer 1
So all you need do is place them in order. The last one goes first and then the second last one.
X to the power of 2 + 4x +5
Answer:
Step-by-step explanations:
