Distribute 2 to x and -2, and -6 to x and -2
2(x - 2) = 2x - 4
-6(x - 2) = -6x + 12
2x - 4 = 4x - 6x + 12
Simplify. Combine like terms
2x - 4 = (4x - 6x) + 12
2x - 4 = -2x + 12
Isolate the x. Add 4 to both sides, and 2x to both sides
2x (+2x) - 4 (+4) = -2x (+2x) + 12 (+4)
2x + 2x = 12 + 4
Simplify
4x = 16
Isolate the x. Divide 4 from both sides
4x/4 = 16/4
x = 16/4
x = 4
4 is your answer for x.
hope this helps
Angle e = x angle d = 5x supplementary means they add up to 180
x + 5x =180
6x = 180
6x/6 = 180/6
x = 30
so angle e = 30 and angle d = 5(30) = 150
The dot product will have you multiply the corresponding coordinates and add up the products
v dot w = (6*(-7)) + (7*5) + (-3*2)
v dot w = -42 + 35 - 6
v dot w = -7 - 6
v dot w = -13
Answer: -13