Find the Expanded Form (x+7)^2+y^2=81

${(x + 7)}^{2} + y^{2} = 81$

Step 1

Simplify the left side ${(x + 7)}^{2} + y^{2}$ .

Simplify each term.

Rewrite ${(x + 7)}^{2}$ as $(x + 7) (x + 7)$ .

$(x + 7) (x + 7) + y^{2} = 81$

Expand $(x + 7) (x + 7)$ using the FOIL Method.

Apply the distributive property.

$x (x + 7) + 7 (x + 7) + y^{2} = 81$

Apply the distributive property.

$x \cdot x + x \cdot 7 + 7 (x + 7) + y^{2} = 81$

Apply the distributive property.

$x \cdot x + x \cdot 7 + 7 x + 7 \cdot 7 + y^{2} = 81$

Simplify and combine like terms.

Simplify each term.

Multiply $x$ by $x$ .

$x^{2} + x \cdot 7 + 7 x + 7 \cdot 7 + y^{2} = 81$

Move $7$ to the left of $x$ .

$x^{2} + 7 \cdot x + 7 x + 7 \cdot 7 + y^{2} = 81$

Multiply $7$ by $7$ .

$x^{2} + 7 x + 7 x + 49 + y^{2} = 81$

Add $7 x$ and $7 x$ .

$x^{2} + 14 x + 49 + y^{2} = 81$

Reorder.

Move $49$ .

$x^{2} + 14 x + y^{2} + 49 = 81$

Move $14 x$ .

$x^{2} + y^{2} + 14 x + 49 = 81$

Step 2

Subtract $81$ from both sides of the equation.

$x^{2} + y^{2} + 14 x + 49 - 81 = 0$

Step 3

Subtract $81$ from $49$ .

$x^{2} + y^{2} + 14 x - 32 = 0$