Answer:
1.4in
Step-by-step explanation:
Length of Photo = 4in
Width of Photo = 3in
Unknown:
Value of X = ?
Solution:
Follow these steps:
Area of a rectangle = l x w
Since the photo is a rectangle; area of photo:
Area of photo = 4in x 3in = 12in²
For the area of the ad;
Length of ad = 4 + x
Width of ad = 3 + x
Given that,
the area of the photo = 
area of ad
12in² = area of ad
Area of ad = 24in²
Area of the ad;
(4 + x) (3 + x) = 24
12 + 4x + 3x + x² = 24
12 + 7x + x² = 24
x² + 7x = 24 - 12
x² + 7x = 12
x² + 7x - 12 = 0
Using the almighty formula where
a = 1, b = 7 and c = -12
x = 
x = ![\frac{-7 + \sqrt[]{-7^{2} - 4x1x-12 } }{2x1}](https://tex.z-dn.net/?f=%5Cfrac%7B-7%20%2B%20%5Csqrt%5B%5D%7B-7%5E%7B2%7D%20-%204x1x-12%20%7D%20%7D%7B2x1%7D)
or ![\frac{-7 - \sqrt[]{-7^{2} - 4x1x-12 } }{2x1}](https://tex.z-dn.net/?f=%5Cfrac%7B-7%20-%20%5Csqrt%5B%5D%7B-7%5E%7B2%7D%20-%204x1x-12%20%7D%20%7D%7B2x1%7D)
x = 1.4 or -8.4
therefore the answer is 1.4in
x is 1.4in
Answer: 30.72 miles per gallon
To find <span>best approximate for the average gas mileage at a speed of 60 miles per hour you need to replace the variable x with 60. The calculation would be:
</span><span> y=−0.0088x2+0.79x+15
y= -31.68 +47.4 + 15
y= 30.72
</span>
<span>(0.5, -1)
f^-1(x) and f(x) are inverse functions of each other. That means that for all x, f^-1(f(x)) = x and f(f^-1(x)) = x. So for f^-1(x) we've been given the point (-1, 0.5) which means that we have an x value of -1 and a y value of 0.5. So if we swap the x and y values, we'll have a valid point for function f(x). Therefore an x value of 0.5 and a y value of -1 will work. So the answer is (0.5, -1). Notice that no math has to be done, you just need to know the meaning of inverse functions.</span>
