Answer:
D
Step-by-step explanation:
Either try all the numbers and see which ones work or do the following.
Times both sides by 2x-5.
3=x(2x-5)=2x^2-5x
Rearrange and solve the quadratic. I will factorise.
2x^2-5x-3=0
(2x+1)(x-3)=0
so x = -1/2 or 3
We can see that revolving the region formed by intersecting 3 lines, we will get 2 cones that are connected their bases.
Volume of the cone V=1/3 *πr²*h
1) small cone has r=5, and h=5
Volume small cone V1= 1/3 *π*5²*5 = 5³/3 *π
2) large cone has r=5, and h=21-6=15, h=15
Volume large cone V2= 1/3 *π*5²*15 = 5³*π
3) whole volume
5³/3 *π + 5³*π=5³π(1/3+1)=((5³*4)/3)π=(500/3)π≈166.7π≈523.6
Area
we see 2 right triangles,
Area of the triangle=1/2*b*h, where b -base, h -height
1) small one, b=5, h=5
A1=(1/2)*5*5=25/2
2)large one, b=5, h=15
A2=(1/2)*5*15=75/2
3)
whole area=A1+A2=25/2+75/2=100/2=
50
If i were you, i would add one to 7x and fifteen. this gives you x^2+8x+16, a perfect square of x+4.
m is 43
add my instagarm @jessica.letendre
-13-56/14+9=
-69/23=-3
-48+36/12=
-12/12=-1