How do you solve for x in this using trignometric ratios

One of the same side angles of two parallel lines is 20° smaller than the other one. find the measures of these two angles.

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11