the equation of a circle in expanded form is shown. what is the equation of the circle in standard form? use…

the equation of a circle in expanded form is shown. what is the equation of the circle in standard form? use the drop - down menus to complete the equation. $x^{2}+y^{2}-8x + 4y-16 = 0$ click the arrows to choose an answer from each menu. ( choose... )$^{2}+$( choose... )$^{2}=$ choose... $^{2}$
Answer
Explanation:
Step1: Group x - terms and y - terms
$(x^{2}-8x)+(y^{2}+4y)-16 = 0$
Step2: Complete the square for x - terms
For $x^{2}-8x$, we add $(\frac{-8}{2})^2=16$ inside the parentheses. $(x^{2}-8x + 16)+(y^{2}+4y)-16-16=0$ $(x - 4)^{2}+(y^{2}+4y)-32 = 0$
Step3: Complete the square for y - terms
For $y^{2}+4y$, we add $(\frac{4}{2})^2 = 4$ inside the parentheses. $(x - 4)^{2}+(y^{2}+4y+4)-32 - 4=0$ $(x - 4)^{2}+(y + 2)^{2}=36$ $(x - 4)^{2}+(y + 2)^{2}=6^{2}$
Answer:
$(x - 4)^{2}+(y + 2)^{2}=6^{2}$