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

$x=\frac{170}{10}=17$

The value of x is 17