Step-by-step explanation:
Puzzle 1
(a + bi) (c + di)
ac + adi + bci + bdi²
(ac − bd) + (ad + bc)i
Matching coefficients:
30 < ac − bd < 80
ad + bc = 0
We need to pick four integers between -9 and 9 such that these two equations are satisfied. One possible combination is:
a = 8, b = -4, c = 6, d = 3
The number would be:
ac − bd = (8)(6) − (-4)(3) = 60
Puzzle 2
Using the result from Puzzle 1:
ac − bd = 34
ad + bc = 8
Like before, it makes sense to assume b is negative. With some trial and error, one possible answer is:
a = 5, b = -6, c = 2, d = 4