Question

Expand the brackets and simplify the surds: Please explain your steps:
1. (7√5 + 2) (√5 + 4)
2. (1 - 3√7) (6 - 3√7)

Answer 1

Ello !!

Here's your answer

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• Simplifying the following :-

1. ( 7√5 + 2 ) ( √5 + 4 )

= √5 ( 7√5 + 2 ) + 4 ( 7√5 + 2 )

= 7 × √5 × √5 + 2 × √5 + 4 × 7√5 + 4 × 2

= 35 + 2√5 + 28√5 + 8

= 43 + 30√5

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2. (1 - 3√7) (6 - 3√7)

= 1 (6 - 3√7) - 3√7 (6 - 3√7)

= 6 - 3√7 - 18√7 + 9 × 7

= 6 + 63 - 21√7

= 69 - 21√7

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Hope it helps you dear!

★ Devil king

Answer 2

1. (7√5 + 2) (√5 + 4)
={(7root5)*(root5)+(2)*(root5)}+{(7root5)*(4)+(2)*(4)}
={35+2root5}+{28root5+8}
=35+2root5+28root5+8
=43+30root5
2. (1 - 3√7) (6 - 3√7)
={(1)*(6)+(-3root7)*(6)}+{(1)*(-3root7)+(-3root7)*(-3root7)}
={(6)+(-18root7)}+{(-3root7)+(63)}
=6-18root7-3root7+63
=69-21root7