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".
You can put it in a graphing calculator.
X Y
-2 59.64
-1 59.82
0 60
1 60.18
2 60.36
Thats it. and you just graph it
Answer:
x = -4
Step-by-step explanation:
3x + 5 = x - 3
Subtract x from each side
3x+5-x = x-3-x
2x+5 = -3
Subtract 5 from each side
2x+5-5 = -3-5
2x = -8
Divide each side by 2
2x/2 = -8/2
x = -4
Answer:
7 hours
Step-by-step explanation:
47+23=70
1hour = 70 toys
? = 490 toys
Then you cross multiply:
1hour*490 toys= 490/70 = 7 hours
____________
70 toys
20 because of the whole is 40 and the shaded part is by 20 you just take half of 40 and you get 20
