The given system of equations is:
y = 4x − 3 ...(1)
2x + 7y = 41 ...(2)
Notice that the first equation is a solved equation for y. So, we can simply substitute 4x-3 for y in equation (2) to solve. This method is also knwon as substitution method by which we can plug in one equation into other equation.
So, if we will substitute y=4x-3 in equation (2) then we will get,
2x+7(4x-3)=41
Hence, third choice 2x + 7(4x − 3) = 41 is the correct answer.
