2x^2 + 8x - 12 = 0..divide by 2
x^2 + 4x - 6 = 0
x^2 + 4x = 6...add 4 to both sides of the equation
x^2 + 4x + 4 = 6 + 4
(x + 2)^2 = 10....<== ur constant is 10
x + 2 = (+-)sqrt 10
x = -2 (+ - ) sqrt 10
x = -2 + sqrt 10
x = -2 - sqrt 10
Answer: a standard door is about 2-2.10 meters
Step-by-step explanation:
Answer:
3. How many faces do each of the following have?
- cube - 6 faces
- square pyramid - 5 faces
- triangular pyramid - 4 faces
- pentagonal pyramid - 6 faces
Hope this helps!