The numbers are both equal because, 6.80 is six and eight hundredths, and 6.8 is six and eight tenths. When writing decimals any zero added to the end of the number has no value, 8/10 as a fraction is equal to 80/100 if simplified, so Nicky and Marta wrote equal numbers. :)
11. You’ve done it correctly
12. Let x^2=y
y^2+13y+40=0
(y+8)(y+5)=0
y=8, 5
Since y=x^2
x^2=8 x^2=5
x=+/-√5 x= +/-2√2
13. x^4-x^2-x^2-8=0
x^4-2x^2-8=0
let x^2=y
Y^2-2y-8=0
(y-4)(y+2)=0
y=4, -2
Since y=x^2
X^2=4 X^2=-2
X= +/- 2 This wouldn’t be a real solution
14. It’s pretty much the same process, just substitute y in for x^2. If you’re confused feel free to ask and I can do it, or you can put it through Photomath
15. You’re on the right track so I’m just going to continue from where you left off
x^2(4x+5)-4(x+5)=0
(x^2-4)(4x+5)=0
x= +/- 2 4x=5
x=5/4 or 1 1/4
Hope this helped :)
Using the assumed values, the volume of the cone is 
<h3>How to determine the volume of the cone?</h3>
The volume of a cone is calculated using:

The parameters are not given.
So, we use the following assumed values
Radius, r = 5
Height, h =10
Using the assumed values, we have:

Evaluate the product

Hence, using the assumed values, the volume of the cone is 
Read more about volumes at:
brainly.com/question/1972490
#SPJ1
Answer:
4:1 or 4/1
Step-by-step explanation:
Original surface area: Each side is 1 * 1 = 1 and there are 6 sides, so 1 * 6 = 6.
New surface area: Each side is 2*2 = 4, and there are 6 sides, so 4 * 6 = 24
The ratio would be 24:6, or 4:1. As a fraction, this would be 4/1
Step-by-step explanation:
