Z1=(12-i) z2=(-1- i) z3(4+3i) z4(-3-2 I) z3*z4-z2*z1

To calculate z3z4 - z2z1, we need to perform the following calculations:

z3 * z4: (4 + 3i) * (-3 - 2i)

Multiplying the real parts: 4 * (-3) = -12

Multiplying the imaginary parts: 3i * (-3) = -9i

Multiplying the real part of z3 with the imaginary part of z4: 4 * (-2i) = -8i

Multiplying the imaginary part of z3 with the real part of z4: 3i * (-3) = -9i

Add the results together: -12 - 9i - 8i - 9i = -12 - 26i

Now let's calculate z2 * z1: (-1 - i) * (12 - i)

Multiplying the real parts: -1 * 12 = -12

Multiplying the imaginary parts: -1 * (-i) = i

Multiplying the real part of z2 with the imaginary part of z1: -1 * (-i) = i

Multiplying the imaginary part of z2 with the real part of z1: -1 * 12 = -12

Add the results together: -12 + i + i - 12 = -24 + 2i

Now we can calculate z3z4 - z2z1: (-12 - 26i) - (-24 + 2i)

Distribute the negative sign: -12 - 26i + 24 - 2i

Combine like terms: -12 + 24 - 26i - 2i

Combine the real parts: 12 - 26i - 2i

Combine the imaginary parts: 12 - 28i

So, z3z4 - z2z1 = 12 - 28i.