(a) Give the value of for which the system of equations
has an infinite number of solutions.
(b) With as in your answer to part (a), find a particular solution to this system.
If, when you're solving simultaneous equations, there's an infinite number of solutions, then the equations are not independent. In the case of 2 equations in 2 unknowns, this simply means that one equation is a multiple of the other. So here, , and both sides of the second equation are clearly twice the first.
When , any value of will do to find a corresponding value of .