(-x²-2x+6)+(-9x²-7x+6) = -x²-2x+6-9x²-7x+6 = -10x² - 9x + 12
Answer:
813.4 cm² (nearest tenth)
Step-by-step explanation:
<u>Volume of a cylinder</u>

Given:
Use the Volume of a Cylinder formula and the given values to find the <u>radius of the cylinder</u>:



<u>Surface Area of a Cylinder</u>

Substitute the given value of h and the found value of r into the formula and solve for SA:




Therefore, the surface area of the cylinder is 813.4 cm² (nearest tenth)
We have that
y=x²----> equation 1<span>
y=x+2-----> equation 2
multiply equation 1 by -1
-y=-x</span>²
add equation 1 and equation 2
-y=-x²
y=x+2
------------
0=-x²+x+2-------------> -x²+x+2=0-----> x²-x-2=0
Group terms that contain the same variable, and move the
constant to the opposite side of the equation
(x²-x)=2
<span>Complete
the square. Remember to balance the equation by adding the same constants
to each side
</span>(x²-x+0.5²)=2+0.5²
Rewrite as perfect squares
(x-0.5)²=2+0.5²
(x-0.5)²=2.25-----> (x-0.5)=(+/-)√2.25-----> (x-0.5)=(+/-)1.5
x1=1.5+0.5-----> x1=2
x2=-1.5+0.5---- > x2=-1
for x=2
y=x²----> y=2²----> y=4
the point is (2,4)
for x=-1
y=x²----> y=(-1)²---> y=1
the point is (-1,1)
the answer isthe solution of the system are the points(2,4) and (-1,1)
Answer:
D
Step-by-step explanation:
To be an identity we require both sides of the equation to equate
A
8x + 9 ≠ 8x - 3 ← not an identity
B
7x - 2 = 8x + 4 - x = 7x + 4 ≠ 7x - 2 ← not an identity
C
11 - (2x + 3) = 11 - 2x - 3 = - 2x + 8 ≠ - 2x - 8 ← not an identity
D
5x + 8 - x = 6x - 2(x - 4), that is
4x + 8 = 6x - 2x + 8 = 4x + 8 ← both sides equate thus an identity