If you would like to know what is the sum of 667 and 23, you can calculate this using the following steps:
the sum of 667 and 23:
667 + 23 = 690
The correct result would be B. 690.
I don't like these algebra problems which pretend to be geometry.
These are supplementary angles adding to 180 degrees; geometry done.
7x - 1 + 3x - 9 = 180
10 x = 190
x = 19
ABC=3x - 9 = 3(19) - 9 = 48
Answer 48°
K=8k+28
subtract 8k from both side
-7k = 28
divide both side by -7
k= -4