Answer:
The statement
is a contingency.
The statement
is a contradiction.
Step-by-step explanation:
A tautology is a proposition that is always true.
A contradiction is a proposition that is always false.
A contingency is a proposition that is neither a tautology nor a contradiction.
a) To classify the statement
, you need to use the logic laws as follows:

by the logical equivalence involving conditional statement.
by the Commutative law.
by Distributive law.
by the Commutative law.
by the Negation law.
Therefore the statement
is a contingency.
b) To classify the statement
, you need to use the logic laws as follows:

by the logical equivalence involving conditional statement.
by the Commutative law.
by Distributive law.
by the Negation law.
Therefore the statement
is a contradiction.
Answer:
x=4 and y=4
Step-by-step explanation:
From first function we have:

And from the second one:

Substitute them:

A(c - b) = d
ac - ab = d
ac = d + ab
c = (d + ab)/a