Question

Calculati : a) 2-√28-3+√63

b) √54-√24-√180+6√5

c) √0,8+2√1,8-8√0,2

d) √3,38-√0,98-√5.12

Answer 1

a) 2-√28-3+√63=2-4√7-3+3√7=-1-√7

b) √54-√24-√180+6√5==3√2-2√6-6√5+6√5=3√2-2√6

c) √0,8+2√1,8-8√0,2 =√8/10+2√18/10-8√2/10=√80/10+2√180/10-8√20/10=4√5/10+2*6√5/10-8*2√5/10=0/10=0

d) √3,38-√0,98-√5.12 =√338/100 - √98/100-√512/100=√338/10 - √98/10-√512/10=13√2/10-7√2/10-16√2/10=-10√2/10=-√2