1. a) 3√7 + 2√7 + 10√7 = ( 3 + 2 + 10 )√7 = 15√7
b) 8√2 + 12√2 + 3√2 = ( 8 + 12 + 3 )√2 = 23√2
c) 10√5 - 3√5 + 2√5 = ( 10 - 3 + 2 )√5 = 9√5
d) - 3√3 + 8√3 + 6√3 - 9√3 = ( - 3 + 8 + 6 - 9 )√4 = ( - 12 + 14 )√3 = 2√3
2. a) 3√11 + ( - 2√11 + 9√11 ) - 10√11 =
= 3√11 + 7√11 - 10√11 = ( 3 + 7 - 10 )√11 = 0
b) 2√2 - ( 3√2 - 6√2 + √2 ) - √2 =
= 2√2 - ( - 2√2 ) - √2 =
= 2√2 + 2√2 - √2 = 4√2 - √2 = 3√2
c) ( 20√6 + 12√6 ) - ( 4√6 - 2√6 ) = 32√6 - 2√6 = 30√6
d) ( 33√7 - 50√7 ) + ( - 3√7 - 5√7 + √7 ) =
= ( - 17√6 ) + ( - 7√7 ) = - 17√7 - 7√7 = - 24√7
