Answer:
1) x ∈ R
2) y ∈ R
Explanation:
* Lets explain something very important when we solve an equation
of one variable
- If we have an equation of x then the solution is one of these cases
# x has only one value
# x has no value
# x can be any value
- The first case when we solve for x and the answer is one value
- The second when x disappear and the left hand side of the
equation not equal the right hand side
- The third when x disappear and the left hand side of the
equation equal the right hand side
* Lets solve the problem
1)
∵ x - 27 = -(27 - x)
- Multiply the bracket (27 - x) by (-)
- Remember (-)(+) = (-) and (-)(-) = (+)
∴ x - 27 = -27 + x
- Subtract x from both sides and add 27 to both sides
∴ x - x = -27 + 27
∴ 0 = 0
∵ The left hand side = the right hand side
∴ x can be any real number
∴ x ∈ R ⇒ R is the set of real number
2)
∵ 6y - 8 = 2(3y - 4)
- Multiply the bracket (3y - 4) by 2
∴ 6y - 8 = 6y - 8
- Subtract 6y from both sides and add 8 to both sides
∴ 6y - 6y = -8 + 8
∴ 0 = 0
∵ The left hand side = the right hand side
∴ y can be any real number
∴ y ∈ R ⇒ R is the set of real number