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:
6.2
Step-by-step explanation:
Although there's multiple ways to solve this problem, my method will be to simply find the area for the full triangle (the empty + orange triangles) and subtract the area of the smaller, empty triangle.
Now, you that area for a triangle is 1/2*base*height.
To find the measurements for the full triangle, you must add up the bases for the two smaller triangles:
Height is the same for both triangles so Height total = 4 ft.
Now the total area can be calculated:
Area total= 1/2* base_total * height_total
Area total = 1/2 * 5ft * 4 ft
Area total = 20 / 2 = 10 ft squared
Lastly, subtract the area of the empty triangle from the total triangle to find the orange triangle.
Area Empty Triangle = 1/2 * base_empty * height_empty
Area Empty Triangle = 1/2 * 1.9ft * 4 ft = 7.6 ft / 2 = 3.8 ft squared
Area total - Area empty = 10ft^2 - 3.8ft^2 = 6.2 ft squared
Answer:
a = 10/3.
Step-by-step explanation:
We write the linear function as follows:
f(x) = mx + b where m is the slope and b is the y-intercept.
f(6) = 6m + b = 8
f(2) = 2m + b = 20 Subtracting these 2 equations:
4m = -12
m = -3.
and -3 * 2 + b = 20 so:
b = 20 + 6 = 26.
So we have the linear function:
f(x) = -3 x + 26
f(a) = 16 = -3 a + 26
-3 a = 16-26
a = -10 * -3 = 10/3.
Answer:its c
Step-by-step explanation:
that is how i would do it.
