Solve by Factoring 9x^2=49

$9 x^{2} = 49$

Step 1

Subtract $49$ from both sides of the equation.

$9 x^{2} - 49 = 0$

Step 2

Rewrite $9 x^{2}$ as ${(3 x)}^{2}$ .

${(3 x)}^{2} - 49 = 0$

Step 3

Rewrite $49$ as $7^{2}$ .

${(3 x)}^{2} - 7^{2} = 0$

Step 4

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 3 x$ and $b = 7$ .

$(3 x + 7) (3 x - 7) = 0$

Step 5

If any individual factor on the left side of the equation is equal to $0$ , the entire expression will be equal to $0$ .

$3 x + 7 = 0$

$3 x - 7 = 0$

Step 6

Set $3 x + 7$ equal to $0$ and solve for $x$ .

Set $3 x + 7$ equal to $0$ .

$3 x + 7 = 0$

Solve $3 x + 7 = 0$ for $x$ .

Subtract $7$ from both sides of the equation.

$3 x = - 7$

Divide each term in $3 x = - 7$ by $3$ and simplify.

Divide each term in $3 x = - 7$ by $3$ .

$\frac{3 x}{3} = \frac{- 7}{3}$

Simplify the left side.

Cancel the common factor of $3$ .

Cancel the common factor.

$\frac{3 x}{3} = \frac{- 7}{3}$

Divide $x$ by $1$ .

$x = \frac{- 7}{3}$

Simplify the right side.

Move the negative in front of the fraction.

$x = - \frac{7}{3}$

Step 7

Set $3 x - 7$ equal to $0$ and solve for $x$ .

Set $3 x - 7$ equal to $0$ .

$3 x - 7 = 0$

Solve $3 x - 7 = 0$ for $x$ .

Add $7$ to both sides of the equation.

$3 x = 7$

Divide each term in $3 x = 7$ by $3$ and simplify.

Divide each term in $3 x = 7$ by $3$ .

$\frac{3 x}{3} = \frac{7}{3}$

Simplify the left side.

Cancel the common factor of $3$ .

Cancel the common factor.

$\frac{3 x}{3} = \frac{7}{3}$

Divide $x$ by $1$ .

$x = \frac{7}{3}$

Step 8

The final solution is all the values that make $(3 x + 7) (3 x - 7) = 0$ true.

$x = - \frac{7}{3}, \frac{7}{3}$

Solve by Factoring 9x^2=49

Related Questions

Support LCMGCF.com by disabling your adblocker.