Answer:
$9
Step-by-step explanation:
The breakfast before tip costs x.
The tip is 20% of x.
The tip is $1.80.
20% × x = 1.80
0.2x = 1.8
x = 1.8/0.2
x = 9
Answer: $9
(x,y)=(-2,-5)
y=1/2x-4
y=-2x-9
(y=) 1/2x-4=-2x-9
1/2x +2x=-9+4
1/2x +4/2x=-5
5/2x=-5
5x=-5*2
5x=-10
x=-2
y=-2x-9=-2*(-2)-9=4-9=-5
Check the picture below.
