Answer:
A) w=3
Step-by-step explanation:
4 x 3 = 12
This is the work when you plug in the numbers in the varible w
Answer:
8x+7
Step-by-step explanation:
(2x - y = -2)2
5x - 2y = -7
4x - 2y = -4
Subtract both
x = -3
5(-3) - 2y = -7
-15 - 2y = -7
-2y = 8, y = -4
Solution: (-3,-4)
THe problem is basically telling us: 
where P is the power disappated and V^2 is our voltage squared.

So, for the second example to find the power we simply have to plug k and our voltage back in, so: