3 equivalent ratios or 5/2
10 /4
20/8
30/12
Answer:
15 feet = Length
Step-by-step explanation:
The area of a rectangle is:
Area = Length x Width
The Area is given as 180 square feet (ft2) and the width is given as 12 feet. Let's plug those values into the Area formula to find the length:
Area = Length x Width
180 = Length x 12
Divide both sides of the equation by 12:
180/12 = Length
15 feet = Length
The function, as presented here, is ambiguous in terms of what's being deivded by what. For the sake of example, I will assume that you meant
3x+5a
<span> f(x)= ------------
</span> x^2-a^2
You are saying that the derivative of this function is 0 when x=12. Let's differentiate f(x) with respect to x and then let x = 12:
(x^2-a^2)(3) -(3x+5a)(2x)
f '(x) = ------------------------------------- = 0 when x = 12
[x^2-a^2]^2
(144-a^2)(3) - (36+5a)(24)
------------------------------------ = 0
[ ]^2
Simplifying,
(144-a^2) - 8(36+5a) = 0
144 - a^2 - 288 - 40a = 0
This can be rewritten as a quadratic in standard form:
-a^2 - 40a - 144 = 0, or a^2 + 40a + 144 = 0.
Solve for a by completing the square:
a^2 + 40a + 20^2 - 20^2 + 144 = 0
(a+20)^2 = 400 - 144 = 156
Then a+20 = sqrt[6(26)] = sqrt[6(2)(13)] = 4(3)(13)= 2sqrt(39)
Finally, a = -20 plus or minus 2sqrt(39)
You must check both answers by subst. into the original equation. Only if the result(s) is(are) true is your solution (value of a) correct.
You have 2x^2 + 9x -9 and 3x^2 -2x +14
To find total area add the two polynomials together by combining the like terms.
2x^2 + 3x^2 = 5x^2
9x + -2x = 9x-2x = 7x
-9 + 14 = 5
Total area = 5x^2 + 7x + 5