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%.
First you would need to convert the equation to match the y = mx + b format.
Subtract 2x from both sides to get -y = -2x + 3
Then, divide -1 (because that's the coefficient to -y, on all values, turning to equation into
y = 2x - 3 (negative and negative makes a positive that's why the 2 value is now positive) in order to make the y value positive.
Our y intercept is -3 so start your graphing line on the -3 value on the x axis.
Our slope is 2/1 which means to go up 2 point and right 1 point, since it's a positive slope.
You can mark every point in order to get a more accurate line and just connect the dots from there. Be sure to use a ruler or some sort of straightedge for a better line.
Hope this helped :)
