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Work Shown:
x = (4+6i)^2
x = (4+6i)(4+6i)
x = y(4+6i) ...... let y = 4+6i
x = 4(y)+6i(y) ..... distribute
x = 4(4+6i)+6i(4+6i) .... plug in y = 4+6i
x = 16+24i+24i+36i^2 ..... distribute again
x = 16+24i+24i+36(-1) .... use the fact that i^2 = -1
x = 16+24i+24i-36
x = 16-36+24i+24i
x = -20+48i
