Someone explain how to get the answer and what the answer is so I can do the other one please

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem

Is trapezoid abdc the result of a dilation of trapezoid mnpq by a scale factor of ? why or why not? yes, because ab and cd are each the lengths mn and qp. yes, because sides ab and cd are parallel to sides mn and qp. no, because ab is the length mn but cd is the length qp. no, because sides ab and cd have different slopes from sides mn and qp.

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11