Tessa made a mistake solving the equation 4(2x + 3 ) = -20. select the line in which her mistake appears.
line 1. 4 (2x + 3) = -20
line 2. 8x + 12 = -20
line 3. 8x = -8
line 4. x = -1

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.

15.8 miles of .