Question

1) efetue as expressoes a)(2i+4)*(-3-5i) b)4i(2i-5)+5(-4i-3) c)(3i-2)ao quadrado d)(3i-4)4-5(3i+8) e)(i+5)+(3i+8)-(4i-7)

Answer 1

a) (5+3i)(2+4i) = 10+20i+6i+12i² = 10+26i-12 = -2+26i

b) (8-2i)(4+5i) = 32+40i-8i-10i² = 32+32i+10 = 42+32i

c) (-4-4i)(2-3i) = -8+12i-8i+12i² = -8+4i-12 = -20+4i

d) (8+3i)(8-3i) = 8²-(3i)² = 64-9i² = 64+9 = 73

e) (-8i)(-8i) = 64i² = -64

f) (5-2i)(5-2i) = 25 - 20i + 4i² = 25 - 20i - 4 = 21 - 20i

g) (8-i)(-1+i) = -8+8i+i-i² = -8+9i+1 = -7+9i

h(3-i)(7-i) = 21-3i-7i+i² = 21-10i-1 = 20-10i

i) -10(3i) = -30i

j) (4-2i)(-1+2i) = -4+8i+2i-4i² = -4+10i+4 = 10i

BOA NOITE!