Question

calculati:a) (√6-2√5)+(1-2√3-5√6)-(2√3-8√5+√6+9)=
b) (4√5 .(-3√5)=
c) (-15√7):+5√3)

Answer 1

a) (√6-2√5)+(1-2√3-5√6)-(2√3-8√5+√6+9)=
√6-2√5+1-2√3-5√6-2√3+8√5-√6-9=
6√5-4√3-8=
2(3√5-2√3-4)

b) (4√5)·(-3√5)=
4·(-3)·(√5)²=
(-12)·5=
(-60)

c) (-15√7):(+5√3)=
(-15):(+5)·(√7):(√3)=
(-3)·√21/3=
-√21