Sum/difference:
Let
This means that
Now, assume that 
is rational. The sum/difference of two rational numbers is still rational (so 5-x is rational), and the division by 3 doesn't change this. So, you have that the square root of 8 equals a rational number, which is false. The mistake must have been supposing that was rational, which proves that the sum/difference of the two given terms was irrational
Multiplication/division:
The logic is actually the same: if we multiply the two terms we get
if again we assume x to be rational, we have
But if x is rational, so is -x/15, and again we come to a contradiction: we have the square root of 8 on one side, which is irrational, and -x/15 on the other, which is rational. So, again, x must have been irrational. You can prove the same claim for the division in a totally similar fashion.
Answer:
x = - 
Step-by-step explanation:
(x - 3) - 5 = 
(x - 1)
Multiply through by 8 to clear the fractions
6(x - 3) - 40 = x - 1 ← distribute parenthesis and simplify left side
6x - 18 - 40 = x - 1
6x - 58 = x - 1 ( subtract x from both sides )
5x - 58 = - 1 ( add 58 to both sides )
5x = - 57 ( divide both sides by 5 )
x = -
Answer:
b) f(x) = x + 6
Step-by-step explanation:
The coordinate (0, 6) makes the y-intercept = 6. Only one of these functions has that intercept: f(x) = x + 6. If you plug in each coordinate the outputted y-value matches up, making this the right answer.
