Let m the tens digit and n the ones
the Original number is 10m+n
7(m+n) =10m+n
7m+7n=10m+n
6n=3m
Reversing the number 10n+m
10n+m=18+n+m
9n=18
n=2
6n=3m
6(2)=3m
3m=12
m=4
the number is 10m+n=10(4)+2=42
We can represent the base as z and the height as 2z+6. We are going to use the formula A=1/2*b*h and solve for z
180=1/2*z*(2z+6)
360=2z^2+6z
0=2z^2+6z-360
0=2(z^2+3z-180)
0=(z+15)(z-12)
So z=-15 and 12 but it must be positive so then the base is equal to 12
When we plug this into 2z+6 we get 30 for the height
2(12)+6=30
Hope this helps
Answer:
At a speed of 57 mph for 8 hr a driver will travel 456 mi
Step-by-step explanation:
Here we have a summary of the letters for each variable:
Speed ---> r (in units of mph)
Time ---> t (in units of hr)
Distance ---> d (in units of mi)
These three variables are related by the next formula:
d = rt
In the data they give to you: 57 mph and 8 hr, they are telling you the r and the t, respectively:
r = 57 mph
t = 8 hr
The only thing you have to do is replace the values:
d = rt ----> d = 57 mph x 8 hr
d = 456 mi
Cylinder:
V = pi * r^2 * h
V = 3.14 * 9^2 * 11
Simplify exponent:
V = 3.14 * 81 * 11
Multiply:
V = 2797.74
Sphere:
V = 4/3 * pi * r^3
V = 4/3 * 3.14 * 9^3
Simplify exponent:
V = 4/3 * 3.14 * 729
Multiply:
V = 3052.08
Cone:
V = 1/3 * pi * r^2 * h
V = 1/3 * 3.14 * 12^2 * 20
Simplify exponent:
V = 1/3 * 3.14 * 144 * 20
Multiply:
V = 3014.4
So the Sphere holds the most.
Answer:
80 cubes
Step-by-step explanation:
volume of one small cube = 1 /2 × 1 / 2 × 1 / 2
= 1 / 8cm^3
let x be the number of cubes needed
1 / 8 × x = 10
x = 10 × 8
x = 80 cubes
