1.
[tex] 4 \pm \sqrt{49} = 4 \pm 7 = [/tex] 4 + 7 or 4 - 7 = 11 or -3
2.
pi is a real number. It is not imaginary or complex, so it definitely belongs to the set of real numbers.
pi is not a whole number or a rational number. It cannot be written as a fraction of integers. pi is irrational.
Therefore, pi is real and irrational.
