Bonjour,

Ex 1

√8×√2

=√(8×2)

=√16

=√4

√3×√27

=√(3×27)

=√81

=9

(5√2)²

=5²×√2²

=25×2

=50

√34/√4

=√(17×2)/2

=(√17×√2)/2

=√17/√2

√112/√28

=√(7×16)/√(7×4)

=4√7/2√7

=4/2

=2

(√7 +3)²

=√7²+2×3×√7+3²

=7+9+6√7

=16+6√7

(3√7 +4)(3√(7-4))

=(3√7 +4)(3√3)

=3√3 × 3√7+4×3√3

=9√21 + 12√3

3/5+√5×(√5/10)

=3/5+1/10

=(6+1)/10

=7/10

√3/2(1/√3 -2√3)

=(√3/2)×(1/√3)-(√3/2)×(2√3)

=1/2-3

=(1-6)/2

= -5/2