Answer: Answers are in the steps read carefully!
Step-by-step explanation:
A) 3x^2 - 7x + 2 To factor this polynomial, you have to find two numbers that their product is 6 and their sum is -7. The numbers -1 and -6 works out because -6 times -1 is 6 and -6 plus -1 is -7.
Now rewrite the polynomial as
3x^2 - 1x - 6x + 2 Now group it
(3x^2 - 1x) (-6x+2) Factor it by groups
x (3x -1) -2(3x -1) Now factor out 3x-1
(3x -1) (x-2) Done!
B) 2x^2 - x -3 Now the same way.You will have two numbers that their product is -6 and their sum is -1. You may be wondering how I get -6 .I get -6 by multiply the leading coefficient 2 by the constant -3. The numbers -3 and 2 works out. Because -3 times 2 is -6 and -3 plus 2 is -1.
Rewrite the polynomial as
2x^2 +2x - 3x -3 GRoup them and factor them
(2x^2 + 2x) (-3x-3)
2x(x+1) -3(x+1) Factor out x+1
(x+1) (2x -3) Done!
C) 3x^2 - 16x - 12 Find two numbers that their product is -36 and their sum is -12. The numbers -18 and 2 works out because -18 times 2 is -36 and -18 plus 2 is -16.
Rewrite the polynomial
3x^2 +2x -18x - 12 GRoup them
(3x^2 + 2x) (-18x - 12) Factor them
x (3x +2) -6(3x +2) Factor out 3x+2
(3x+2) (x -6) Done !
Answer:
(-5, 0) ∪ (5, ∞)
Step-by-step explanation:
I find a graph convenient for this purpose. (See below)
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When you want to find where a function is increasing or decreasing, you want to look at the sign of the derivative. Here, the derivative is ...
f'(x) = 4x^3 -100x = 4x(x^2 -25) = 4x(x +5)(x -5)
This has zeros at x=-5, x=0, and x=5. The sign of the derivative will be positive when 0 or 2 factors have negative signs. The signs change at the zeros. So, the intervals of f' having a positive sign are (-5, 0) and (5, ∞).
Answer:
y = 2x + 10
Step-by-step explanation:
Find the slope:
12 - 2 / 1 - (-4)
10 / 5 = 2
Write in point-slope form:
y - 12 = 2(x - 1)
rearrange:
y - 12 = 2x - 2
y = 2x + 10
The x-intercept is + 6 and the y-intercept is + 10
The first and the third equation can be solved by using the zero product property. Let us examine each equation.
4x²+16x=0
4x(x+4)=0
4x=0 and x+4=0
where x1=0 and x2=-4
Next answer is whown below:
(x+4)(x-12)=0
x1=-4 and x2=12
Therefore, the first and the third equations are the answers.