For a, x is equal to the sum of the measures of the inside angle because the total degrees of a triangle is 180 and the total degrees of a line is 180. Since both the line and the triangle are missing the same amount, x would equal the interior degrees that are listed. I don’t know what m<x means for b, but if it’s asking for the value of x it’s 62+78= 140° which makes the missing interior angle 40°. Hope this helps!
