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(1) a = , b = . a and b are irrational, but a+b = 1 is rational.
a = , b = . a and b are irrational, and a+b = is irrational.
(2) a = , b = . a and b are irrational, but a-b = 1 is rational.
a = , b = . a and b are irrational, and a-b = is irrational.
(3) a = , b = . a and b are irrational, but a*b = 2 is rational.
a = , b = . a and b are irrational, and a*b = is irrational.
(4) a = , b = . a and b are irrational, but a/b = 1 is rational.
a = , b = . a and b are irrational, and a/b = is irrational.
Solved.