2. (06.01) if you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the first equation is substituted into the second equation. 15x − y = −6 5x − 3y = −13 (1 point) 5(−15x − 6) − 3y = −13 5(15x + 6) − 3y = −13 5x − 3(15x + 6) = −13 5x − 3(−15x − 6) = −13