Step-by-step explanation:

Answer:
C. 
Step-by-step explanation:
Given that A and B are matrices and
is a scalar, then the distributive property of scalar multiplication over addition is given by;

The distributive property of scalar multiplication over subtraction is

The correct answer is C.
Answer:
What are you asking?
Step-by-step explanation:
4x - 8 + 6x + 13 = 90
4x + 6x = 90 + 8 - 13
10 x = 85
10x/10 = 85/10
x = 8.5