Answers:
L = 4
M = -3
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Step-by-step explanation:
On the left side, the number 20-12i is in the form a+bi where a = 20 and b = -12
On the right side, 5L+(4M)i is in the form a+bi where a = 5L and b = 4M
Equating the real parts a = 20 and a = 5L has us get
5L = 20
5L/5 = 20/5
L = 4
Do the same with the imaginary parts as well
b = -12
b = 4M
4M = -12
4M/4 = -12/4
M = -3