Question

(5-x)(5+x)=(x-4)²-7
Helpp((

Answer 1

`\displaystyle\\ (5-x)(5+x)=(x-4)^2-7\\\\ 5^2 - x^2 = x^2-8x + 16 -7\\\\ -x^2 -x^2+8x + 25 -16+7=0\\\\ -2x^2 + 8x +16=0\\\\ x_(12)= (-b\pm √(b^2-4ac) )/(2a)= (-8\pm √(64-4\cdot(-2)\cdot 16) )/(2\cdot(-2))=\\\\ = (-8\pm √(64+ 128) )/(-4)= (-8\pm √(192) )/(-4)= (-8\pm √(64\cdot 3) )/(-4)=\\\\ =(-8\pm 8√( 3) )/(-4)=2\mp 2√( 3)\\\\ \boxed{\bf x_1 = 2-2√( 3)}\\\\ \boxed{\bf x_2 = 2+2√( 3)}`