Sum is the result of adding so
12 + x, but i don't see it as a option.
5x² + 5x + 2x + 2
5x(x + 1) + 2(x + 1)
(5x + 2)(x + 1)
Answer:
This is a line, x>0 (miles cannot be negative)
Step-by-step explanation:
Cost of renting a car = cost per mile times the number of miles plus the flat fee
We know the cost per mile = .25 and the flat fee
Let x = number of miles and y = cost of renting a car
y = .25x+15
This is in the form y= mx+b which is the slope intercept form of a line.
Since the problem is given all the total walking distance, the first thing we are going to do is find the total distance in the map:


Now that we have the distance in the map, we can establish a ratio between the walking distance and the distance in the map:

We can conclude that each inch the map represents 0.5 miles of walking distance.
By "which is an identity" they just mean "which trigonometric equation is true?"
What you have to do is take one of these and sort it out to an identity you know is true, or...
*FYI: You can always test identites like this:
Use the short angle of a 3-4-5 triangle, which would have these trig ratios:
sinx = 3/5 cscx = 5/3
cosx = 4/5 secx = 5/4
tanx = 4/3 cotx = 3/4
Then just plug them in and see if it works. If it doesn't, it can't be an identity!
Let's start with c, just because it seems obvious.
The Pythagorean identity states that sin²x + cos²x = 1, so this same statement with a minus is obviously not true.
Next would be d. csc²x + cot²x = 1 is not true because of a similar Pythagorean identity 1 + cot²x = csc²x. (if you need help remembering these identites, do yourslef a favor and search up the Magic Hexagon.)
Next is b. Here we have (cscx + cotx)² = 1. Let's take the square root of each side...cscx + cotx = 1. Now you should be able to see why this can't work as a Pythagorean Identity. There's always that test we can do for verification...5/3 + 3/4 ≠ 1, nor is (5/3 + 3/4)².
By process of elimination, a must be true. You can test w/ our example ratios:
sin²xsec²x+1 = tan²xcsc²x
(3/5)²(5/4)²+1 = (4/5)²(5/3)²
(9/25)(25/16)+1 = (16/25)(25/9)
(225/400)+1 = (400/225)
(9/16)+1 = (16/9)
(81/144)+1 = (256/144)
(81/144)+(144/144) = (256/144)
(256/144) = (256/144)