Use the quadratic formula to solve the quadratic equation 10x2+5x=5x−8

. Express its solutions in the form a±bi
.(1 point)

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
13 hours ago

To solve the quadratic equation \( 10x^2 + 5x = 5x - 8 \), first, we need to rearrange it into standard form \( ax^2 + bx + c = 0 \).

Starting with the original equation:

\[ 10x^2 + 5x = 5x - 8 \]

Subtract \( 5x \) from both sides:

\[ 10x^2 + 5x - 5x = -8 \]

This simplifies to:

\[ 10x^2 = -8 \]

Now, add \( 8 \) to both sides to set the equation to zero:

\[ 10x^2 + 8 = 0 \]

Next, we can rewrite this as:

\[ 10x^2 + 0x + 8 = 0 \]

Here, we have \( a = 10 \), \( b = 0 \), and \( c = 8 \).

Now we can apply the quadratic formula:

\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]

Substituting in the values of \( a \), \( b \), and \( c \):

\[ x = \frac{-0 \pm \sqrt{0^2 - 4 \cdot 10 \cdot 8}}{2 \cdot 10} \]

Calculating under the square root:

\[ x = \frac{0 \pm \sqrt{0 - 320}}{20} \]

This simplifies to:

\[ x = \frac{\pm \sqrt{-320}}{20} \]

Noting that \( \sqrt{-320} = \sqrt{320}i \):

\[ \sqrt{320} = \sqrt{64 \cdot 5} = 8\sqrt{5} \]

Thus, we have:

\[ x = \frac{\pm 8\sqrt{5}i}{20} \]

This can be simplified:

\[ x = \frac{\pm 2\sqrt{5}i}{5} \]

Finally, we can write the solutions in the form \( a \pm bi \):

\[ x = 0 \pm \frac{2\sqrt{5}}{5}i \]

Therefore, the solutions to the quadratic equation are:

\[ x = 0 \pm \frac{2\sqrt{5}}{5}i \]