Question

What are the steps to solve-x^2+45=4x

Answer 1

`x\text{ = -9 or x = 5}`

Step-by-step explanation:

Here, we want to solve for the value of x

We start by rearranging the given equation

We have that as:

`\begin{gathered} -x^2+45\text{ = 4x} \\ -x^2-4x+45\text{ = 0} \end{gathered}`

We can use the quadratic formula here

We have that as:

`x\text{ = }(-b\pm√(b^2-4ac))/(2a)`

where:

a is the coefficient of x^2 which is -1

b is the coefficient of x which is -4

c is the third number which is 45

Substituting the values, we have it that:

`x\text{ = }(4\pm√(-4^2-4(-1)(45)))/(2(-1))`
`\begin{gathered} x\text{ = }\frac{4\pm\sqrt{16\text{ + 180}}}{-2} \\ \\ x\text{ = }(4\pm√(196))/(-2) \\ \\ x\text{ = }(4\pm14)/(-2) \\ \\ x\text{ = }(4+14)/(-2)\text{ or }(4-14)/(-2) \\ \\ x\text{ = }(18)/(-2)\text{ or }(-10)/(-2) \\ \\ x\text{ = -9 or 5} \end{gathered}`