Question

#8, 9 help me please!
Very heavy in algebra and geometry (

Answer 1

8. We need to multiply numbers under the root

$\sqrt{18*72*16} =\sqrt{20736} =144$

9.

$x^{2} - 6x=16\\x^{2}-6x-16=0\\D= 36 - 4*(-16)=100\\\\\sqrt{D} =10\\x_{1} =(6+10)/2=8\\x_{2}=(6-10)/2=-2\\Answer = -2$