Answer:
Length: 23.38
Width: 3.34
Step-by-step explanation:
First I drew out a diagram so that I could visibly see the problem. [ a rectangle with 7x on one side and x on the other.
So to find the area you multiply length time width and 7x times x is 7x^2. The actual area is given: 78, so you set that equal to 7x^2.
Then you want to divide by 7 to get 11.14. Then you want to take the square root of 11.14 to get 3.338 which rounds to 3.34 {try not to round until the very end]. This gives you the width of the rectangle, so to find the length you would have to multiply x by 7 to get 23.38. When you multiply the length and width (3.34 x 23.38) you get 78.08 which can round to 78.
7x^2 = 78
x^2 = 78/7
x^2= 11.142...
x = sqrt(1.142...)
x = 3.338 --> 3.34 --> width
3.34 x 7 --> 23.38 --> length
3.34 x 23.38 --> 70.8
The required equation of the parabola is (y-5)² = 20(x+2)
<h3>Equation of a parabola</h3>
The standard equation of a parabola is expressed as;
(y-k)² = 4p(x-h)
where;
vertex = (h, k)
focus = (p+k, k)
directrix x = -p + h
Note that the directrix given will determine the type of the equation of a parabola
Given the following parameters
focus = (-2, 5) = (h, k)
x = -p + h
3 = p -2
p = 5
Substitute
(y-k)² = 4p(x-h)
(y-5)² = 4(5)(x-(-2))
(y-5)² = 20(x+2)
Hence the required equation of the parabola is (y-5)² = 20(x+2)
Learn more on equation of parabola here; brainly.com/question/4061870
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(3y + 7) + (5y-7)= 8y
(4y - 5)- 8y= -4y-5
Answer:
-3
Step-by-step explanation:
3*-3=-9
-9-20=-29