Упростите (√7-√12)×(√7+2√3)

Question

Упростите (√7-√12)×(√7+2√3)

Answer 1

(√7-√12).(√7+2√3)=(√7-√(4.3)).(√7+2√3)=(√7-2√3)(√7+2√3)=
=(√7)²-(2√3)²=7-12=-5