Step-by-step explanation:
Remember that the sum of angles on a straight line are supplementary. (180°)
Therefore 3x + 2 + 6x - 20 = 180.
=> 9x - 18 = 180
=> 9x = 198
=> x = 22.
MN + NP = MP
6x - 7 + 2x + 3 = 60
8x - 4 = 60
8x = 64
x = 8
MN = 6(8) - 7 = 56 - 7 = 49
answer
x = 8
MN = 49