Answer:
6
Step-by-step explanation:
I learned this last year
Each of these roots can be expressed as a binomial:
(x+1)=0, which solves to -1
(x-3)=0, which solves to 3
(x-3i)=0 which solves to 3i
(x+3i)=0, which solves to -3i
There are four roots, so our final equation will have x^4 as the least degree
Multiply them together. I'll multiply the i binomials first:
(x-3i)(x+3i) = x²+3ix-3ix-9i²
x²-9i²
x²+9 [since i²=-1]
Now I'll multiply the first two binomials together:
(x+1)(x-3) = x²-3x+x-3
x²-2x-3
Lastly, we'll multiply the two derived terms together:
(x²+9)(x²-2x-3) [from the binomial, I'll distribute the first term, then the second term, and I'll stack them so we can simply add like terms together]
x^4 -2x³-3x²
<u> +9x²-18x-27</u>
x^4-2x³+6x²-18x-27
a)
A = 5m × 7m = 35 m²
b)
A = 4cm×8cm/2 = 4cm×4cm = 16 cm²
c)
A = 1,2km×0,8km/2 = 0,96km²/2 = 0,48 km²
d)
A = (8m + 10m)·3m/2 = 18m·3m/2 = 9m·3m = 27 m²
