Answer:
Step-by-step explanation:
<u>Given</u>
- DE = 3x + 2, EF = x + 5, DF = 23
<u>As per segment addition postulate</u>
<u>Substituting values:</u>
- 3x + 2 + x + 5 = 23
- 4x + 7 = 23
- 4x = 16
- x = 4
10!=3628800
10-3=7
7!=5040
3628800/5040=720
Answer:
(3, 5)
Step-by-step explanation:
y = 2x - 1
3x + 2y = 19
In the second equation, substitute 2x - 1 in for y, since y equals 2x - 1 in the first equation. Solve for x.
3x + 2(2x - 1) = 19
3x + 4x - 2 = 19
7x - 2 = 19
7x - 2 + 2 = 19 + 2
7x = 21
7x/7 = 21/7
x = 3
Pick the first equation to solve for y since it says y =. Substitute 3 in for x.
y = 2x - 1
y = 2(3) - 1
y = 6 - 1
y = 5
The total surface area of a regular tetrahedron is calculated through the equation,
SA = (sqrt 3) x a²
Substituting the known value,
SA = (sqrt 3) x (10 cm)² = 173.20 cm²
Its volume is obtained by,
V = ((sqrt 2)/ 12) x a³
V = ((sqrt 2) / 12) x (10 cm)³ = 117.85 cm³
Thus, its surface area and volume are 173.20 cm² and 117.85 cm³, respectively.
