To solve by completing square method we proceed as follows:
2x^2+16x=-18
dividing through by 2 we get:
x^2+8x=-9
but
c=(-b/2a)^2
c=(-8/2)=16
hence
x^2+8x+16=-9+16
x^2+8x+16=7
(x+4)(x+4)=7
(x+4)^2=7
thus getting the square root of both sides
x+4=+/-√7
x=-4+/-√7
x=
Answer:
D. 980.2 cm
Step-by-step explanation:
Surface area of cylinder = 2¶r2 + 2¶rl
r = radius
l = lenght
¶ = 3.142
S. A = (2X3.142X6^2) + (2X3.142X6X20)
= 226.224 + 754.08 = 980.3cm2
