Answer:
She should use 32.5 g of the sample that contains 14%
Step-by-step explanation:
Here, we want to know the number of grams of the sample that contains 14% copper that should be used
let the number of grams that contains 14% copper to be used be x
Then the number of grams of 22% will be 130-x
Thus, mathematically;
0.14(x) + 0.22(130-x) = 0.2(130)
0.14x + 28.6 - 0.22x = 26
0.22x - 0.14x = 28.6 - 26
0.08x = 2.6
x = 26/0.08
x = 32.5
The answer is 30. 2x6 is 12 so you would do 5x6 which is 30
Answer:J
Step-by-step explanation:
Answer:
The sum of the roots is 0.5
Step-by-step explanation:
<u><em>The correct question is</em></u>
What is the sum of the roots of 20x^2-10x-30
we know that
In a quadratic equation of the form
The sum of the roots is equal to
in this problem we have
so

substitute
<u><em>Verify</em></u>
Find the roots of the quadratic equation
The formula to solve a quadratic equation is equal to


substitute





The roots are x=-1 and x=1.5
The sum of the roots are
----> is ok