Unit rate means how much does it cost for 1 unit
140 for 18ft^2
divide by 18
140/18=7.77777777777777
so the unit rate is $7.78 per square foot
- x + y = 7
y = x + 7
slope = 1
perpendicular slope = -1
at point (-1, -1),
y = mx + c
-1 = -1 (-1) + c
-1 = 1 + c
c = -1 -1
c = - 2
equation:
y = -x -2
y + x = -2 or - x - y = 2
Hey! :)
So when we write something in slope intercept form, all we're doing is solving for y. So let's do that with this equation!
-2x + y = 9
add 2x to both sides
y = 2x + 9
So C is your answer.
Please let me know if you need anything further explained!
