y^2+y-72=0
quadratic equation
Answers
Answer:
How to solve your problem
2
+
−
7
2
=
0
y^{2}+y-72=0
y2+y−72=0
Quadratic formula
Factor
1
Use the quadratic formula
=
−
±
2
−
4
√
2
y=\frac{-{\color{#e8710a}{b}} \pm \sqrt{{\color{#e8710a}{b}}^{2}-4{\color{#c92786}{a}}{\color{#129eaf}{c}}}}{2{\color{#c92786}{a}}}
y=2a−b±b2−4ac
Once in standard form, identify a, b and c from the original equation and plug them into the quadratic formula.
2
+
−
7
2
=
0
y^{2}+y-72=0
y2+y−72=0
=
1
a={\color{#c92786}{1}}
a=1
=
1
b={\color{#e8710a}{1}}
b=1
=
−
7
2
c={\color{#129eaf}{-72}}
c=−72
=
−
1
±
1
2
−
4
⋅
1
(
−
7
2
)
√
2
⋅
1
y=\frac{-{\color{#e8710a}{1}} \pm \sqrt{{\color{#e8710a}{1}}^{2}-4 \cdot {\color{#c92786}{1}}({\color{#129eaf}{-72}})}}{2 \cdot {\color{#c92786}{1}}}
y=2⋅1−1±12−4⋅1(−72)
2
Simplify
Evaluate the exponent
Multiply the numbers
Add the numbers
Evaluate the square root
Multiply the numbers
=
−
1
±
1
7
2
y=\frac{-1 \pm 17}{2}
y=2−1±17
3
Separate the equations
To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.
=
−
1
+
1
7
2
y=\frac{-1+17}{2}
y=2−1+17
=
−
1
−
1
7
2
y=\frac{-1-17}{2}
y=2−1−17
4
Solve
Rearrange and isolate the variable to find each solution
=
8
y=8
y=8
=
−
9
y=-9
y=−9
Solution
=
8
=
−
9