Total students = 28
Students with brown eyes = 19
students wear glasses = 13
Not brown eyes or no glasses = 7
Not brown eyes = 28 - 19 = 9
Not wearing glasses = 28 - 13 = 15
Not brown eyes and wearing glasses = 15 - 9 = 6
Brown eyes and wearing glasses = 13 - 6 = 7 <==== answer
That's unusual: repetition: -1/2 - 1/2.
Did you perhaps mean "Factor -1/2 out of (-1/2)x + 6?
Let's do that. Let's rewrite 6 as (-1/2)(-12).
Then (-1/2)x + 6 (-1/2)x -(1/2)(-12)
-------------- = ------------------------ = x - 1/2
-1/2 -1/2
Hope that's what you wanted. If not, please try to apply a similar approach to solving this particular problem.
Answer:
First one-3
Second one-0
Last one-12
Step-by-step explanation: