Step-by-step explanation:



Answer:
x+75=180
x=180-75
x=105
Step-by-step explanation:
x and a are on a straight line
a straight line=180
so you add the x to a=180
Answer:
6 hours
Step-by-step explanation:
because if they work together it will be 9 hours slower than Kelsey's time alone.
not sure if correct
Answer:
see graph of y=3/4 x-4
Step-by-step explanation:
Assuming you mean

Below is a graph of that one. The slope is 3/4 and the interception with the y axis is at y=-4. The equation is in its normal form y=ax+b with a=3/4 (slope) and b=-4 (y intercept), so no conversion needed.
You have to be careful on how you write these equations down. It might very well be that you meant:
or 
However, those are more complex so I'm hoping for the first one... ;-)