Question

if an angles (13x+30) and (5x+6) are supplementary angles find the measure of these angles

Answer 1

13x+30+5x+6 = 180
18x+36 = 180
18x = 180-36 => 144
x = 144/18 = 8°
hope this helps

Answer 2

Two angles are said to be supplementary, if there sum is 180°. 
Here, we have two supplementary angles (13x+30)° and (5x+6)°, which means that their sum is 180°. 
Let's write this statement in the form of an equation and solve for x. 
$13x + 30 + 5x + 6 = 180$
$13x + 5x + 30 + 6 = 180$
$18x + 36 = 180$
$18(x + 2) = 18(10)$          [Just making the equation little bit easier to solve. ]
$\frac{18(x+2)}{18} = \frac{18(10)}{18}$
$x + 2 = 10$
$x + 2 - 2 = 10 - 2$
$x = 8$
Now, we have found the value of x, so, we can also find out the angles. 
(13x+30)° = (13×8+30)° = (104+30)° = 134°
(5x+6)° = (5×8+6)° = (40+6)° = 46°
∴ The two supplementary angles are 134° and 46°. 

Hope this may help you.