Question

Calcule as seguintes multiplicações:

A) (6+4i) (2+3i) =
B) (5+6i) (5+6i) =
C) (7+8i)²

Answer 1

Answer:

A. 26i

B. 36i^2 + 60x + 25

C. 64x^2 + 112x + 49

Step-by-step explanation:

To get answer in question A, B, and C, use FOIL method

FOIL Method:

$(a + b)(c + d) = ac + ad + bc + bd$

(pretend x is i)

Question A:

$(6 + 4x)(2 + 3x) \\ 12 + 18x + 8x - 12 \\ 26x$

Question B:

$(5 + 6x)(5 + 6x) \\ {(5 + 6x)}^{2} = {36x}^{2} + 60x + 25$

Question C

$(7 + 8x)(7 + 8x) \\ {64x}^{2} + 112x + 49$