A. x²-14x+49; is a polynomial
Step-by-step explanation:
(x-7)² can be written as (x-7)(x-7)
Expanding the expression
x(x-7)-7(x-7)
x²-7x-7x+49
x²-14x+49 ⇒⇒A quadratic function, which is a polynomial of degree 2
This function demonstrates the closer property of multiplication in that the change in order of multiplication does not change the product. This is called commutative property.
(x-7)(x-7)
-7(x-7)+x(x-7)
-7x+49+x²-7x
x²-14x+49
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Polynomials :brainly.com/question/9601478
Keywords : product, closure property of multiplication,
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Answer: thousand place
Step-by-step explanation:
hope this helps
Answer:
Step-by-step explanation:
Let x = the current of the river
Then 21 + x = the speed going downstream (with the current)
a nd 21 - x = the speed going upstream (against the current)
Distance = speed × time
d = st
t = d/s
Time going downstream = time going upstream
Check:
OK
Answer:
Step-by-step explanation:
A line has the following slope-intercept equation:
In which a is the slope.
Write the equation of a line that has a slope of -3 and passes through the point (1.25, -4).
Slope of -3 means that 
. So
Passes through the point (1.25, -4). Means that when 
So
Answer:
a = - 1.1
Step-by-step explanation:
The condition for a single variable function f(x) to be decreasing is f'(x) < 0.
f(x) = 4/x^2 - 6x + 9
Then, differentiating with respect to x on both sides we get,
f(x) = 4(-2)(1/x^3) - 6 < 0
-8/x^3 - 6 < 0
8/x^3 + 6 > 0
{Dividing both sides with - 1 and hence the inequality sign changes}
8/x^3 > -6
8 > - 6x³ {Multiplying both sides with x³}
6x³ > - 8 {Interchanging the sides}
x^3 > -8/6
⇒ x > - 1.1
So, a = - 1.1
