X= a number
29 - 2x= 21
subtract 29 from both sides
-2x= -8
divide both sides by -2
x= 4
CHECK:
29 - 2x= 21
29 - 2(4)= 21
29 - 8= 21
21= 21
ANSWER: The number is 4.
Hope this helps! :)
Answer:
The volume of the regular tetrahedron is 283.5 m³
Step-by-step explanation:
The formula of the volume of the regular tetrahedron is V = 
A h, where
∵ The area of the base of a regular tetrahedron is 98.9 m²
∴ A = 98.9 m²
∵ The height of it is 8.6 m
∴ h = 8.6 m
→ Substitute them in the formula of the volume above
∵ V = (98.9)(8.6)
∴ V = 283.5133333 m³
→ Round it to the nearest tenth of a cubic meters
∴ V = 283.5 m³
∴ The volume of the regular tetrahedron is 283.5 m³
Hi
According to Pythagoras :
The square of hypotenuse is the sum if the square if the two other side
so : 7^2 + X^2 = 25^2
49 + X^2 = 625
X^2 = 625-49
X^2 = 576
this equation as two roots . As a triangle cannot have a negative side value, I will only take positive value
so X = V576 =24
Answer:
28r + 8r + r = 55
Step-by-step explanation:
Some values you know (given or calculated) and some things you do not know.
RATE TIME DISTANCE
BIKE 2*8r 1.75
RUN 8r
SWIM r 1
Total 55
Give a variable to unknown running speed and fill in everything.
RATE TIME DISTANCE
BIKE 16r 1.75 28r
RUN 8r t 8rt
SWIM r 1 r
Total 55
Notice some trouble? WHY? I missed seeing the "ran for one hour". the variable t is KNOWN! This will be corrected here:
RATE TIME DISTANCE
BIKE 16r 1.75 28r
RUN 8r 1 8r
SWIM r 1 r
Total 55
Calculations used to fill out the graph:
Then her running speed was 8r,
and her biking speed was 2*(8r) = 16r.
Swimming for 1 hour, Jenny covered the distance of 1*r = r kilometers.
Biking for 1.75 hour, Jenny covered the distance of 1.75*16r = 28r kilometers.
Running for 1 hour, Jenny covered the distance of 1*2r = 8r kilometers.
Everything is filled and looks good. There is a sum of distances in just the one single variable, r.
Solve for r, and this is the swimming speed.
28r + 8r + r = 55
