algebra
posted by Kelsie .
Factor each polynomial comletely.
4x^218
7x^2847
4x^2+18

4x^218 = (2x + sqrt18)(2x  sqrt18)
= 4[x + (3/2)sqrt2][x  (3/2)sqrt2]
On the second one, factor out the 7 and recognize that 121 = 11^2. Ypu will have the difference of two squares.
The third one requires imaginary factors.
4x^2 + 18 = 4(x^2 + 2*9/4)
= 4[x + i(3/2)sqrt2][ x  i(3/2)sqrt2]