Let t = the number of days the mouse travels
Let D = the distance that the mouse traveled
The mouse travels at a rate of 1.5 miles per day, so R = 1.5 mi/day
The equation is:
Distance (D) = Rate (R) x Time (t)
SO:
Distance (D) = 1.5 mi./day X Time (t)
        
             
        
        
        
Number 1 a and d are true 
number to its b c and d
number 3 idk, sorry
        
             
        
        
        
The line through (a,b) with slope m is
y-b = m(x-a)
Here that's 
y + 1 = (3/4) (x - 2)
Let's multiply by 4 to clear the fractions and distribute the constants,
4y + 4 = 3x - 6
Rearranging into standard form,
3x - 4y = 10
Check.  The slope is 3/4, good. 3(2) - 4(-1) = 6+4 = 10 good
Answer: 3x - 4y = 10