Question

solve this question and say the answer​

Answer 1

Answer :

c) 21

Solution :

• Given : √(19 - 4√x) = √12 - √7
• To find : x = ?

We have ;

√(19 - 4√x) = √12 - √7

Now ,

Squaring both the sides , we get ;

=> 19 - 4√x = (√12 - √7)²

=> 19 - 4√x = (√12)² + (√7)² - 2•√12•√7

=> 19 - 4√x = 12 + 7 - 2•2√3•√7

=> 19 - 4√x = 19 - 4√21

=> -4√x = -4√21

=> √x = √21

=> x = 21

Hence x = 21 .