To answer the 1 and 2 just put 0 on the variable other than the intercept you are looking for, if your looking for X, then Y = 0 so...
(Option D)1. -10x+5y=40
intercept on X
-10x + 5(0)=40
-10x=40 (divide by -10 to take x alone)
x= -4
intercept on Y
-10(0)+5y=40
5y=40 (divide by 5)
y=8
(Option D) 2. same procedure
int. X
5x +4y =80
5x + 4(0) = 80
x = 16
int y.
5(0) + 4y = 80
y = 20
3. just put in standard mode
y= (1/6)x + 4 (multiply by 6 so you have dont have fractions)
6y= x+ 24 (move x to the other side)
-x + 6y = 24
