Will mark brainilest. what's the formula to find the accounts balance

Answer this 30 points and brainliest!

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

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