Answer:
The question mark is 10. x is 2.
Step-by-step explanation:
The question mark is 10. Divide Both Sides by five. x=2.
Answer:
Step-by-step explanation:
8
Answer:
No it doesnt
Step-by-step explanation:
It doesnt, because the x values or domain repeat here. It would be a functionif the x didnt repeat. Y can repeat but x cant. Hope it helps. Feel free to ask questions. God bless you
Knowing that cos(45°) = 1/√2 is the way forward.

The last step in the equation may not be obious, but the trick here is to multiple numerator and denominator with (1-√2), then the denominator has the special product (a+b)(a-b) = a²-b².
There is no solution for the first one
if you eliminate y you get 2 equations
-13x - 13z = -25
-13x - 13x = -15
- there is no solution to theses
a23 means the element in the second row and the 3rd column
so its -5