[tex]\huge\text{Hey there!}[/tex]
[tex]\large\text{Equation: 10x - 9 = 9x}\\\large\text{SUBTRACT 9x to BOTH SIDES}\\\large\text{10x - 9x - 9x = 9x - 9x}\\\large\text{Cancel -9x - 9x because it gives you 0}\\\large\text{Keep: 9x - 9x because it helps us solve for our equation}\\\large\text{9x - 9x = 0}\\\large\text{New equation: x - 9 = 0}\\\large\text{ADD 9 to BOTH SIDES}\\\large\text{x - 9 + 9 = 0 + 9}\\\large\text{Cancel: -9 + 9 because it gives you 0}\\\large\text{Keep: 0 + 9}\\\large\text{0 + 9 = x}\\\large\text{\underline{\bf{x = 9}}}[/tex]
[tex]\large\text{Solving for }\angle\large\text{7}\rightarrow\mathsf{\sqrt{81}}\large\text{ = 9 * 9}\rightarrow\large\text{81}\\\\\large\text{Solving for }\angle\text{6}\rightarrow \large\text{180 - 81 = ANSWER}\\\\\large\text{180}^\circ\large\text{ - 81}^\circ\large\text{= 99}^\circ[/tex]
[tex]\boxed{\boxed{\large\text{Answer: \bf{C. 99}}\bf{^\circ}}}[/tex]
[tex]\text{Good luck on your assignment and enjoy your day!}[/tex]
~[tex]\frak{Amphitrite1040:)}[/tex]
