n = necklace
b = bracelet
n +b =120
n = 120-b
3.50n + 2.50b = 330
11n + 5b = 880
3.5(120-b) +2.5b=330
420-3.5b + 2.5b = 330
420 -b = 330
-b = -90
B =90
N = 30
3.5*30= 105
2.5*90 = 225
225 +105 = 330
11*30 = 330
90*5 = 450
450 +330 = 780
90 bracelets and 30 necklaces
X + y - z = 9
3x - y + z = -13
____________(+)___
4x = -4 => x = -1 => y - z = 10;
But, x - 2y + 4z = -1 => -2y + 4z = 0 => -y + 2z = 0;
y - z = 10
-y + 2z = 0
_________(+)__
/ z = 10 => y = 20 .
A. There is one solution. The solution is ( - 1, 20, 10 ).
The answer is H, you cannot make such conclusion
We have to multiply given (3-2i)(3+2i)
(3-2i)(3+2i)=9-6i+6i+4i^2
9+4i^2
We know that i^2=-1, so lets substitute it
9+4*(-1)=9-4=5
