Answer:

Step-by-step explanation:
use substitution method
Answer:
The Greatest common factor (GCF) of 40 and 42 is 2.
(Hope this helps! Btw, I answered first. Brainliest please!! :D)
Answer:
letter tiles
Step-by-step explanation:
Our three axioms A1,A2 and A3 for affine plane geometry are consistent since there is at least one model for these axioms. However this system is incomplete because in this system there exist relevant statements which cannot be either proven or disproven. Consider for example the statement A7.
Answer:
x=1+2√2 or x=1−2√2
Step-by-step explanation:
Let's solve your equation step-by-step.
3x2−6x=21
Step 1: Since the coefficient of 3x^2 is 3, divide both sides by 3.
3x2−6x
3
=
21
3
x2−2x=7
Step 2: The coefficient of -2x is -2. Let b=-2.
Then we need to add (b/2)^2=1 to both sides to complete the square.
Add 1 to both sides.
x2−2x+1=7+1
x2−2x+1=8
Step 3: Factor left side.
(x−1)2=8
Step 4: Take square root.
x−1=±√8
Step 5: Add 1 to both sides.
x−1+1=1±√8
x=1±√8
x=1+2√2 or x=1−2√2