To add fractions, first convert them to have equal denominators.
3/4= 9/12 (multiply both sides by 3)
2/3= 8/12 (multiply both sides by 4)
From here, add the numerators while keeping the denominator.
9/12+ 8/12= 17/12
Final answer: 17/12 or 1 5/12
Domain is the x-coordinate and range is the y - coordinate

To find equivalent equations, you simply have to simplify both of these :)
a) 5/6(x - 6) + 1/6(3 - x)
Simplify.
5/6x - 5 + 1/2 - 1/6x
Add like terms.
(5/6x - 1/6x) + (-5 + 1/2)
Simplify.
4/6x +(-4.5)
Simplify.
2/3x - 4.5
b) (y + 7)4 + 8 - 5y
Simplify.
4y + 28 + 8 - 5y
Add like terms.
(4y - 5y) + (28 + 8)
Simplify.
-y + 36
~Hope I helped!~