To find what the number is, we need to set up proportional fractions.
Currently, we have 8% of a number is 20.
To set up our fractions, put 100% under 8% as a fraction first.
It should look like this: 8/100 (hint: per-cent means per-hundred).
Now, we have 20 out of a number, x. This is because we are claiming that 20 is 8% of a number (if we just reword the question without changing the concept).
It should look like this: 20/x.
Our proportional fractions are:
20/x = 8/100.
To solve for this, we need to cross-multiply the denominator of 8/100 (bottom number, 100) with the numerator of 20/x (top number, 20).
This product equation should look like this:
20 x 100 (when simplified, we get 2000).
Now, we need to cross multiply the numerator of 8/100 (top number, 8) with the denominator of 20/x (bottom number, x).
This product equation should look like this:
8x.
Now that we've cross-multiplied, set our two products as an equation.
8x = 2000.
To solve for x, divide both sides by 8 (remember, what you do to one side of an equation, you must do it to the other).
8x / 8 = x
2000 / 8 = 250.
x = 250
Your final answer is:
8% of 250 is 20.
I hope this helps!
Answer: -3 ≤ x ≤ -1
Step-by-step explanation:
1 ≤ 3 - 4x ≤ 9
1 + 3 ≤ - 4x ≤ 9 + 3; Add 3 on all sides
4 ≤ -4x ≤ 12
1 ≤ -x ≤ 3; Divide 4 on all sides
-1 ≥ x ≥ -3; Multiply -1 on all sides(FYI: When multiplying or dividing negative numbers in inequalities, make sure to reverse the signs as well)
Answer:
{- 11, - 1 }
Step-by-step explanation:
Since the coefficient of the x² term is 1 , to complete the square
add (half the coefficient of the x-term )² to both sides
x² + 2(6)x + 36 = - 11 + 36 ← complete the square on the left side
(x + 6)² = 25 ( take the square root of both sides
= ±
x + 6 = ± 5 ( subtract 6 from both sides )
x = - 6 ± 5
x = - 6 + 5 = - 1 or x = - 6 - 5 = - 11
42.5p=c
You get you get the number 42.5 since you know 10 people paid 425, you would divide 425 by 10 to know how much every person paid.
M is representing the amount of money each person paid
(M)10=425
M=425/10
M=42.50 <- since it’s about money
Each person paid $42.50
The cost for 15 people is $637.50.
42.5p=c
42.5(15)=637.5