Question

(11) Simplify: (5+ V7 ) (2 + V5 )



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Answer 1

Question

Simplify: (5+√7)(2+√5)

Solution–

$(5 + \sqrt{7} )(2 + \sqrt{5} ) \\ \\ applying \: \\ (x + y)(a + b) = x(a + b) + y(a + b) \: \: \: \\ in \: it \\ \\ = 5(2 + \sqrt{5} ) + \sqrt{7} (2 + \sqrt{5} ) \\ \\ = 10 + 5 \sqrt{5} + 2 \sqrt{7} + \sqrt{7 \times 5} \\ \\ = 10 + 5 \sqrt{5} + 2 \sqrt{7} + \sqrt{35}$

Points to Remember

• Always care about the signs
• Don't miss any number
• Solve step by step
• Verify the solution at last if required.

Answer 2

value of √7=2.6457

value of √5=2.2360

(5+√7)=7.645

(2+√5)=4.236

7.645×4.236

32.38422