Question

Calculați :
$a)18 - 5 \sqrt{7} - 11 + 3 \sqrt{7}$
$b)4 \sqrt{5} - ( - 2 \sqrt{5} + 2) + 2$
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Answer 1

$a)\quad 18-5\sqrt{7}-11+3\sqrt{7} = 18-11+3\sqrt{7}-5\sqrt{7}= \\ \\ = 7-2\sqrt{7}\\ \\ \\ b)\quad 4\sqrt{5}-(-2\sqrt{5}+2)+2 = 4\sqrt{5}+2\sqrt{5}-2+2 = \\ \\ = 6\sqrt{5}$

Answer 2

Răspuns:

Explicație pas cu pas:

a) 18-11-2√7=7-2√7=√7(√7-2)

b)4√5+2√5-2+2=6√5