Question

solve answer please​

Answer 1

Answer:

c................ .......

Answer 2

Answer:

21

Step-by-step explanation:

$19 - 4 \sqrt{x} = ( \sqrt{12} - \sqrt{7}) {}^{2} \\ 19 - 4 \sqrt{x} = \sqrt{12 {} } {}^{2} + \sqrt{7} {}^{2} - 2 \sqrt{12} \sqrt{7} \\ 19 - 4 \sqrt{x} = 12 + 7 - 2 \sqrt{12} \sqrt{7} \\ - 4 \sqrt{x} = 19 - 2 \sqrt{12} \sqrt{7} - 19 \\ - 4 \sqrt{x} = - 2 \sqrt{12} \sqrt{7 } \\ \sqrt{x} = (2 \sqrt{12} \sqrt{7} ) \div 4 \\ \sqrt{x} = ( \sqrt{12} \sqrt{7} ) \div 2 \\ x = (( \sqrt{12 \ } \sqrt{7) } \div 2) {}^{2} \\ x = (12 \times 7) \div 4 \\ x = 21$