Hello!
1) Let's take this problem in steps:
==> lets first set up some variable for the two angle's measure
--> let's use: 'x' and 'y'
==> two angles are supplementary
--> in other words: the sum of two angles equal 180⁰
x + y = 180
==> larger angle is 15 more than 10 times the smaller angle
--> if 'x' is the larger angle and 'y' is the smaller angle
x = 10y + 15
2) Thus our system of equations are:

3) Let's solve our system of equations:
==> substitute x's value in terms of y from the second equation into the
first equation

==> now substitute y's value into the first equation that we got initially

4) Therefore the two angle's measure are 165 and 15
Answer:
Two angle measure: 165⁰ and 15⁰
System of equations: look at section two
Have a great day!