**Answer: He actually rode 2 miles per hour on his trip**

**Step-by-step explanation: **Maybe unconventional, but express the time it took, then figure the speed.

Time = distance /speed t will represent time, s is the speed: t = 30/s Use the rime it would have taken at the higher speed to create an equation:

t-12 = 30/s+8 replace the y with the 30/s

30/s -12 = 30/s+8

(s)(30/s -12 ) = (s)(30/s+8 ) Cross multiply to cancel denominators

(s-8)(30 -12s) = (s-8)(30s/s+8 ) ==> 30s +240 -12s² -96s =30s Simplify:

(-1)(-12s² -96s +240 ) =0 ==> 12s² +96s -240 divide all by 12

s² + 8s -20 = 0 Factor and solve for s

(s +10)(s -2) =0 s-2=0 ** S= 2 **

**Proof:**

**30/2 = 15 hours for original trip at 2mph, **

**increase speed by 8mph 2 + 8 = 10mph**

**30 miles at 10mph takes 3 hours; that is 12 hours less than his actual trip.**

** (**Brainilest, please :-)

**Answer:**

A, C, D

**Step-by-step explanation:**

Germany was losing WW1, even though they were the 3rd country to be in it. Russia was starting to conquer back lost land, the Ottoman Empire had fallen, Austria-Hungary had surrendered. The Germans were at a loss, so they had to surrender.

Symmetry can be determined visually in a graph. If both graphs are mirror-image of each other, then both of the equations are symmetric. But, you can also determine it analytically through testing the symmetry. These are the rules:

If

f(r, θ) = f(r,-θ), symmetric to the polar axis or the x-axis

f(r, θ) = f(-r,θ), symmetric to the y-axis

f(r, θ) = f(-r,-θ), symmetric to the pole or the origin

Test for symmetry about the x-axis

f(r,θ): r=4 cos3θ

f(r,-θ): r = 4 cos3(-θ) ⇒ r = 4 cos3θ

**∴The graph is symmetric about the x-axis.**

Test for symmetry about the y-axis

f(r,θ): r=4 cos3θ

f(-r,θ): -r = 4 cos3θ

**∴The graph is not symmetric about the y-axis.**

Test for symmetry about the origin

f(r,θ): r=4 cos3θ

f(-r,-θ): -r = 4 cos3(-θ) ⇒ r = -4 cos3θ

**∴The graph is not symmetric about the origin.**

**Answer:**

I dont have one

**Step-by-step explanation: I just need these 50 points srry :(((((((((( **

**Answer:**

330

**Step-by-step explanation:**

3 to the 4th power is 81, then 81 x 3 is 324, then 324+6 is 330