Answer:
x = 17
Explanation:
The two angles form a straight line so they add to 180 degrees
5x-18 + 4x+45 = 180
Combine like terms
9x +27 = 180
Subtract 27 from each side
9x+27-27 =180-27
9x =153
Divide by 9
9x/9 = 153/9
x =17
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