Examples
2x2+3x=52x2+3x=5 , (-1,5)(−1,5)
Step 1
Subtract 55 from both sides of the equation.
2x2+3x-5=02x2+3x−5=0
Step 2
Step 2.1
For a polynomial of the form ax2+bx+cax2+bx+c, rewrite the middle term as a sum of two terms whose product is a⋅c=2⋅-5=-10a⋅c=2⋅−5=−10 and whose sum is b=3b=3.
Step 2.1.1
Factor 33 out of 3x3x.
2x2+3(x)-5=02x2+3(x)−5=0
Step 2.1.2
Rewrite 33 as -2−2 plus 55
2x2+(-2+5)x-5=02x2+(−2+5)x−5=0
Step 2.1.3
Apply the distributive property.
2x2-2x+5x-5=02x2−2x+5x−5=0
2x2-2x+5x-5=02x2−2x+5x−5=0
Step 2.2
Factor out the greatest common factor from each group.
Step 2.2.1
Group the first two terms and the last two terms.
(2x2-2x)+5x-5=0(2x2−2x)+5x−5=0
Step 2.2.2
Factor out the greatest common factor (GCF) from each group.
2x(x-1)+5(x-1)=02x(x−1)+5(x−1)=0
2x(x-1)+5(x-1)=02x(x−1)+5(x−1)=0
Step 2.3
Factor the polynomial by factoring out the greatest common factor, x-1x−1.
(x-1)(2x+5)=0(x−1)(2x+5)=0
(x-1)(2x+5)=0(x−1)(2x+5)=0
Step 3
If any individual factor on the left side of the equation is equal to 00, the entire expression will be equal to 00.
x-1=0x−1=0
2x+5=02x+5=0
Step 4
Step 4.1
Set x-1x−1 equal to 00.
x-1=0
Step 4.2
Add 1 to both sides of the equation.
x=1
x=1
Step 5
Step 5.1
Set 2x+5 equal to 0.
2x+5=0
Step 5.2
Solve 2x+5=0 for x.
Step 5.2.1
Subtract 5 from both sides of the equation.
2x=-5
Step 5.2.2
Divide each term in 2x=-5 by 2 and simplify.
Step 5.2.2.1
Divide each term in 2x=-5 by 2.
2x2=-52
Step 5.2.2.2
Simplify the left side.
Step 5.2.2.2.1
Cancel the common factor of 2.
Step 5.2.2.2.1.1
Cancel the common factor.
2x2=-52
Step 5.2.2.2.1.2
Divide x by 1.
x=-52
x=-52
x=-52
Step 5.2.2.3
Simplify the right side.
Step 5.2.2.3.1
Move the negative in front of the fraction.
x=-52
x=-52
x=-52
x=-52
x=-52
Step 6
The final solution is all the values that make (x-1)(2x+5)=0 true.
x=1,-52
Step 7
Step 7.1
The interval (-1,5) does not contain -52. It is not part of the final solution.
-52 is not on the interval
Step 7.2
The interval (-1,5) contains 1.
x=1
x=1