Answer:
d) 
Step-by-step explanation:
we simplify
by doing 7 x 2 = 14
so it is now

to check, we can use a calculator.
7 to the power of 14 = 678223072849
and
7 to the power of 7, squared also = 678223072849
Hope this helps!
Answer:
3(4.5) Because they equal the same thing
Step-by-step explanation:
4.5(+3)=13.5
3(4.5)=13.5
Answer: 
<u>Step-by-step explanation:</u>
Given: cos x =
, x is in Quadrant 4
Use Pythagorean Theorem to find sin x:
8² + y² = 17²
y² = 17² - 8²
y² = 289 - 64
y² = 225
y = 15
→ sin x = 
Use the double angle formula to find cos (2x):

3x - 4 + x^2 - 1 + 2x^2 - 15
3x^2 + 3x - 20
I wasn't sure if you wanted me to solve for x, but I did anyways.
x ≈ 1.86, or -2.86
Answer:
2a + 3b = 5
b = a - 5
Step-by-step explanation:
2a + 3b = 5
b = a - 5
You can write this another way:
2a + 3(a-5) = 5 ( I added the second formula in the first one )
Now you gotta factor out:
2a + 3a - 15 = 5
Here im gonna do plus 15
2a + 3a = 20 ==> 5a = 20
Now if you divide by 5, you get: a = 4
Now you can fill in the second formula again
b = a - 5 (ill fill this in now)
b = 4 - 5 = -1
So, this makes:
a = 4 , b = -1