First we notice that angles 1 and (20x+5) are supplementary, and we also notice that angle 1 and (24x-1) are alternate exterior angles. If lines a and b are parallel then the exterior angles mentioned before should be equal. If this happens we have that:
[tex]\begin{gathered} 24x-1+20x+5=180 \\ 44x+4=180 \\ 44x=180-4 \\ 44x=176 \\ x=\frac{176}{44} \\ x=4 \end{gathered}[/tex]Once we know the value of x, then we can plug it in the expression for angle 1:
[tex]24(4)-1=95[/tex]Therefore the value of 1 that proves that the lines are parrallel is 95°.