16 thru 23 look wrong and 16 is absolutely wrong. You use this:https://www.mathpapa.com/algebra-calculator.html to work out the answers and it shows the steps and explains it to you better than I could. Good luck
3x + 11.63 = 20
3x + 11.63 - 11.63 = 20 - 11.63
3x = 8.37
by subtracting the 11.63 from both sides, this tells us how much the grapes cost....not per lb., but for the total of all the grapes.
7.) the equation of the circle is
(x - 3)^2 + (y - 4)^2 = 25
If you substitute the point in you get
(6-3)^2 + (8-4)^2 = 25
3^2 + 4^2 = 25
9 + 16 = 25
25 = 25
Both sides of the equation are the same so it proves it lies on the circle
8.) you add the x coordinates together and divide by 2
7 + 4 = 11
11/2 = 5.5
You use +7 because you need to find the midpoint.
You then add 5.5 to - 7 or - 5.5 from 4
-7 + 5.5 = - 1.5
You do the same for y coordinates
6+5 = 11
11/2 = 5.5
6-5.5 = 0.5
So the coordinates of Rachel's house are
(-1.5, 0.5)