Step-by-step explanation:
Given c = longest of triange = 15m
Given b = short side of triangle = 9m
By pythagoras' Theorem,

28 tries. The ratio is 5:7, so once you multiply 5 by 4 to get 20, you do the same to 7 to get 28.
Begin solving like you normally would. Add 2.25 to both sides and subtract 9x from both sides to try getting all x values on one side. However, you will find that after subtracting 9x from both sides, all x values go away, and you end with -2.25=1.6. This is not true (-2.25 is not 1.6), so the answer is no solution. There is no value of x which satisfies that equation.