Answer:
b=12
Step-by-step explanation:
definition is valid since center is exactly 1radius away from any point on the outersurface.
other figures do not fit this defn
It would take May 20 weeks to pay off the car.
Answer:
We have to prove,
(A \ B) ∪ ( B \ A ) = (A U B) \ (B ∩ A).
Suppose,
x ∈ (A \ B) ∪ ( B \ A ), where x is an arbitrary,
⇒ x ∈ A \ B or x ∈ B \ A
⇒ x ∈ A and x ∉ B or x ∈ B and x ∉ A
⇒ x ∈ A or x ∈ B and x ∉ B and x ∉ A
⇒ x ∈ A ∪ B and x ∉ B ∩ A
⇒ x ∈ ( A ∪ B ) \ ( B ∩ A )
Conversely,
Suppose,
y ∈ ( A ∪ B ) \ ( B ∩ A ), where, y is an arbitrary.
⇒ y ∈ A ∪ B and x ∉ B ∩ A
⇒ y ∈ A or y ∈ B and y ∉ B or y ∉ A
⇒ y ∈ A and y ∉ B or y ∈ B and y ∉ A
⇒ y ∈ A \ B or y ∈ B \ A
⇒ y ∈ ( A \ B ) ∪ ( B \ A )
Hence, proved......
