Answer:
A rational number is a number that can be written as a fraction, is a whole number, is a decimal that stops like 3.35, or is a repeating decimal
Step-by-step explanation:
y = x - 2
x + y = 12
Substitute the first expression for y into the second equation.
x + (x - 2) = 12
2x - 2 = 12
2x = 14
x = 7
Now plug into either equation to find y.
y = 7 - 2
y = 5
So the solution is (7, 5).
Answer:

And replacing we got:

And we can calculate this probabilit using the normal standard distribution or excel and we got:

Step-by-step explanation:
If we define the random variable of interest "the amount spent by a family of four of food per month" and we know the following parameter:

And we want to find the following probability:

And we can use the z score formula given by:

And replacing we got:

And we can calculate this probabilit using the normal standard distribution or excel and we got:

Answer:
x ≤ 3
Step-by-step explanation:
Given
2(4 + 2x) ≥ 5x + 5 ← distribute parenthesis on left side
8 + 4x ≥ 5x + 5 ( subtract 4x from both sides )
8 ≥ x + 5 ( subtract 5 from both sides )
3 ≥ x , hence
x ≤ 3