Question

Помогите пожалуйста, (задание на фото) 

Answer 1

$1. = 2 sqrt{x} +8 sqrt{x} -9 sqrt{x} = sqrt{x} (8+2-9)= sqrt{x}$
2. =$sqrt{3y*4} - 0.5 sqrt{12y*4} + 2 sqrt{27y*4} = 2 sqrt{3} - sqrt{2y} +4 sqrt{27}= 2 sqrt{3y} - sqrt{3*4y}+4 sqrt{3*9y}= sqrt{3y}(2-2+12)=12 sqrt{3y}$
3. =$sqrt{3} ( sqrt{3*9} - sqrt{12*4} )= sqrt{3}(3 sqrt{3} -2 sqrt{12})= sqrt{3}(3 sqrt{4} -4 sqrt{3} )=3 sqrt{9}-4 sqrt{9} = 9-12=-3$
4. = $5 sqrt{49}- sqrt{9*49} * sqrt{49*2} = 35 - 7 sqrt{9} +7 sqrt{2} =35-21+7 sqrt{2} =14+7 sqrt{2}$
5. =$3 sqrt{2} (2-5 sqrt{16*2} )-2 sqrt{9*2} =3 sqrt{2} (2-20 sqrt{2} )-6 sqrt{2} =3 sqrt{4}-60 sqrt{4} -6 sqrt{2}= 6-120-6 sqrt{2} =-114-6 sqrt{2}$
6. = $sqrt{4*3} -( sqrt{15} -3 sqrt{5} ) sqrt{5} =2 sqrt{3} ( sqrt{75}-3 sqrt{25} )= 2 sqrt{3} -5 sqrt{3} +15=15-3 sqrt{3}$

*Добавила №2. №3 и №4