So if talking about points on a graph then a. x is made negative or opposite of what it is basically, the x point would go x units from the zero line in the other way it is currently ie. reflected across the x axis
b. both x and y are positive, basically the figure would be reflected across the x axis then reflected across the y axis (or y axis then x, doesn't matter)
c. y times 2 y is 2 times as high (gets bigger)
d. 2/3 times x x is 2/3 as much as it was before (gets smaller)
e. 1/2 x and 1.5 y x get's half smaller and y gets 1.5 bigger (x gets smaller, y gets bigger)
No she doesn't have enough money. All you do is multiply 8.60 by .2 which come out to 1.72 and 8.60 plus 1.73 which equals 10.33 so she needs 33 more cents tone able to tip 20%.