Question

Fine the value of x in(2x+5)(8x+5)

Answer 1

We are given the value of two angles as functions of "x"

`\begin{gathered} \text{angle 1 = 2x+5;} \\ \text{angle 2 = 8x+5} \end{gathered}`

These are supplentary angles, that is, their sum is 180 degrees

`\text{angle 1 + angle 2 =180}^(\circ)`

Replacing the values for the angles

`(2x+5)+(8x+5)=180`

Now we solve the equation, first by adding similar terms

`10x+10=180`

Now we substract 10 on both sides

`10x=170`

Now we divide by 10 on both sides

`x=(170)/(10)=17`

The value of x is 17