First translate the English phrase "Four times the sum of a number and 15 is at least 120" into a mathematical inequality.
"Four times..." means we're multiplying something by 4.
"... the sum of a number and 15..." means we're adding an unknown and 15 and then multiplying the result by 4.
"... is at least 120" means when we substitute the unknown for a value, in order for that value to be in the solution set, it can only be less than or equal to 120.
So, the resulting inequality is 4(x + 15) ≤ 120.
Simplify the inequality.
4(x + 15) ≤ 120
4x + 60 ≤ 120 <-- Using the distributive property
4x ≤ 60 <-- Subtract both sides by 60
x ≤ 15 <-- Divide both sides by 4
Now that we have the inequality in a simplified form, we can easily see that in order to be in the solution set, the variable x can be no bigger than 15.
In interval notation it would look something like this:
[15, ∞)
In set builder notation it would look something like this:
{x | x ∈ R, x ≤ 15}
It is read as "the set of all x, such that x is a member of the real numbers and x is less than or equal to 15".
Answer: m = $52
Explanation:
Tickets (t) = $8
Popcorn & Soda (s)= $5
Friends = 4
Since all friends bought the same thing the equation will be set as
4(t +s) = m OR 4t +4s = m
Using substitution, you plug each variable
t = 8 and s = 5
4((8) + (5)) = m
4(8+5) = m => 4(13) =m => 52=m
OR
4(8) + 4(5) = m => 32 + 20 = m =>
52 =m
Answer:
28
Step-by-step explanation:
so, if mason is 9 and the sheep is 7 year old in dog years
we have to do 7*4 ,because 9,10,11,12=4 that's why u multiply it by 4,and 7 because thats how many years dogs ages for every person that turns a year age
Answer:
80 machines
Step-by-step explanation:
If a machine makes 20 gadgets every fourth (1/4) of an hour, it makes 80 machines every hour (20*4).