How do u find central angle? Please explain well, and no links. Thank you!

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

What is the distance between point a and b

Find the values of the variables in the kite