Please help....?

Question

(2 - 4i) - (5 + 7i)

(SQRT[x] + 3)(SQRT[x] - 3)

2x SQRT(12xy^2)] - [y SQRT(75x^3]

(2 - 3i)(4 + i)

2 / (SQRT[3] - 2)

(1 - 2i) / (-3i)

Answer 1

(2 - 4i) - (5 + 7i) =

2 - 4i - 5 - 7i =

- 3 - 11i

- - - - - - - s-

Answer 2

(2 - 4i) - (5 + 7i)
2 - 4i - 5 - 7i
-3 - 11i

(√[x] + 3)(√[x] - 3)
Factor it! Remember, √[x] = x ^ (.5). So, x^0.5 * x^0.5 = x^1
x -3√[x] + 3√[x] -9
x - 9

(2 - 3i)(4 + i)
Factor again. i^2 = -1 because √[-1] = i. So, √[-1] * √[-1] = i^2 = -1
8 + 2i - 12i + 3
11 - 10i

2 / (√[3] - 2)
multiply both numerator & denominator by (√[3] +2) so the denominator isn't so big.
[2(√[3] +2)] / [(√[3] -2)(√[3] +2)]
[2√[3] + 4] / [3 + 2√[3] - 2√[3] -4]
[2√[3] + 4] / -1
-2√[3] - 4

(1 - 2i) / (-3i)
multiply both numerator & denominator by i since that is what makes the denominator look tough.
(i + 2) / 3