The answer is b. Great job! here ill show you the work.
15x +90 > 270
move constant to the right side and change its sign, like this:
15x>270-90
then subtract the numbers
15x>180
lastly, divide both sides by 15.
hope this helped!
The answer is a = 3/4 = 0.75
First get rid of the paranthesis,

Then set the denominators equal:

Then remove the denominators and solve:

Eliminate -12a^2 by adding 12a^2 to both sides:

Take the fourth root of them or take the square root twice:
![\sqrt[4]{256 {a}^{4} } = \sqrt[4]{81} \\ 4a = 3](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B256%20%7Ba%7D%5E%7B4%7D%20%7D%20%20%3D%20%20%5Csqrt%5B4%5D%7B81%7D%20%20%20%5C%5C%20%204a%20%3D%203)
Divide both sides by 4:
The top left graph is the only one correct. It rises up slowly then faster, and then stays constant for an hour, then decreases.
Billion million Gillian
Idk delete this comment I don't deserve it here not a proper answer :(