Answer:
x = -4, 5/2
Step-by-step explanation:
A quadratic can be solved may ways, including graphing, factoring, and the quadratic formula. You can also check possible answers by making use of the relationships between solutions and the coefficients.
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A graph is attached. It shows the solutions to be -4 and 5/2.
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When factored, the equation becomes ...
(2x -5)(x +4) = 0 . . . . . has solutions x=-4, x=5/2 (these make the factors zero)
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Using the quadratic formula, the solutions of ax^2 +bx +c = 0 are found from ...
x = (-b±√(b²-4ac))/(2a)
x = (-3±√(3²-4(2)(-20))/(2(2)) = (-3±√169)/4 = {-16, +10}/4
x = {-4, 5/2}
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For ax^2 +bx +c = 0, the solutions must satisfy ...
product of solutions is c/a = -20/2 = -10
Only the first and last choices have this product.
sum of solutions is -b/a = -3/2
Only the first choice (-4, 5/2) has this sum.
Answer:
Answers Below
Step-by-step explanation:
Part A:
r=d/t
Part B:
r=665280/3
r=221760
Part C:
221760/5280 = 42mph
Part D: Miles per Hour, because it is easier to understand
Answer:
The dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches
Step-by-step explanation:
We have that:

Let the dimension of the paper be x and y;
Such that:


So:

Substitute 128 for Area

Make x the subject

When 1 inch margin is at top and bottom
The length becomes:


When 2 inch margin is at both sides
The width becomes:


The New Area (A) is then calculated as:

Substitute
for x

Open Brackets

Collect Like Terms



To calculate the smallest possible value of y, we have to apply calculus.
Different A with respect to y

Set

This gives:

Collect Like Terms

Multiply through by 


Divide through by 2

Take square roots of both sides



Recall that:



Recall that the new dimensions are:


So:




To double-check;
Differentiate A'




The above value is:

This means that the calculated values are at minimum.
<em>Hence, the dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches</em>
Answer:
2, 5, 14, 41, 122
Step-by-step explanation:
Using the recursive rule with a₁ = 2
a₂ = 3a₁ - 1 = 3(2) - 1 = 6 - 1 = 5
a₃ = 3a₂ - 1 = 3(5) - 1 = 15 - 1 = 14
a₄ = 3a₃ - 1 = 3(14) - 1 = 42 - 1 = 41
a₅ = 3a₄ - 1 = 3(41) - 1 = 123 - 1 = 122
The first 5 terms are 2, 5, 14, 41, 122
Answer:
18 = m
Step-by-step explanation:
2=m/2-7
Add 7 to each side
2+7=m/2 - 7+7
9 = m/2
Multiply each side by 2
9*2 = m/2 * 2
18 = m