Answer:
x = 7
Step-by-step explanation:
Based on the midsegment theorem of a trapezoid, thus:
NP = (JK + ML)/2
Substitute
45 = (3x + 11 + 10x - 12)/2
2*45 = 13x - 1
90 = 13x - 1
90 + 1 = 13x
91 = 13x
Divide both sides by 13
91/13 = x
7 = x
