Asked and answered elsewhere.
brainly.com/question/10192511Knowing that 1+2i is a root, you also know that 1-2i is a root, so one quadratic factor is
(x -1)² -(2i)² = x^2 -2x +5
Long division of the given polynomial by this quadratic gives a quotient of
x² +9
which has roots ±3i.
Then all
the roots are {-3i, 3i, 1-2i, 1+2i}.
Answer:15.5 because you have to take away some point
Step-by-step explanation:
11) 7 + -10+(4(5+-3)) = 7+-10+8=5
12) (12 +-10)+3x+-1(2x+4x), 12+-10x+3x+-2x+-4x = 12+-13x
The graph of

is shown in the graph below.
The graph is of ∩-shape when the constant

of the quadratic equation

is negative