Solve by Factoring 4x^2+7x-57=0

$4 x^{2} + 7 x - 57 = 0$

Step 1

Factor by grouping.

For a polynomial of the form $a x^{2} + b x + c$ , rewrite the middle term as a sum of two terms whose product is $a \cdot c = 4 \cdot - 57 = - 228$ and whose sum is $b = 7$ .

Factor $7$ out of $7 x$ .

$4 x^{2} + 7 (x) - 57 = 0$

Rewrite $7$ as $- 12$ plus $19$

$4 x^{2} + (- 12 + 19) x - 57 = 0$

Apply the distributive property.

$4 x^{2} - 12 x + 19 x - 57 = 0$

Factor out the greatest common factor from each group.

Group the first two terms and the last two terms.

$(4 x^{2} - 12 x) + 19 x - 57 = 0$

Factor out the greatest common factor (GCF) from each group.

$4 x (x - 3) + 19 (x - 3) = 0$

Factor the polynomial by factoring out the greatest common factor, $x - 3$ .

$(x - 3) (4 x + 19) = 0$

Step 2

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

$x - 3 = 0$

$4 x + 19 = 0$

Step 3

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

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

$x - 3 = 0$

Add $3$ to both sides of the equation.

$x = 3$

Step 4

Set $4 x + 19$ equal to $0$ and solve for $x$ .

Set $4 x + 19$ equal to $0$ .

$4 x + 19 = 0$

Solve $4 x + 19 = 0$ for $x$ .

Subtract $19$ from both sides of the equation.

$4 x = - 19$

Divide each term in $4 x = - 19$ by $4$ and simplify.

Divide each term in $4 x = - 19$ by $4$ .

$\frac{4 x}{4} = \frac{- 19}{4}$

Simplify the left side.

Cancel the common factor of $4$ .

Cancel the common factor.

$\frac{4 x}{4} = \frac{- 19}{4}$

Divide $x$ by $1$ .

$x = \frac{- 19}{4}$

Simplify the right side.

Move the negative in front of the fraction.

$x = - \frac{19}{4}$

Step 5

The final solution is all the values that make $(x - 3) (4 x + 19) = 0$ true.

$x = 3, - \frac{19}{4}$

Solve by Factoring 4x^2+7x-57=0

Related Questions

Support LCMGCF.com by disabling your adblocker.