Final answer:
To solve the system of equations using the substitution method, substitute the second equation into the first equation and simplify. If the resulting equation is a contradiction or does not have a solution, the system has no solution.
Step-by-step explanation:
The given system of equations is:
4x - 7y = -28
y = (4/7)x
To solve this system using the substitution method, we substitute the second equation into the first equation:
4x - 7((4/7)x) = -28
Simplifying the equation, we get:
4x - (4)x = -28
0 = -28
Since 0 does not equal -28, there is no solution to the system of equations. Therefore, the answer is 'none none'.