Math question please help if you get this right I will mark you as a brainliest
1 answer:
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Answer:
see explanation
Step-by-step explanation:
Given
9n² - n - = 0 ← multiply through by 3 to clear the fraction
27n² - 3n - 2 = 0 ← factoring
Consider the factors of the product of the n² term and the constant term which sum to give the coefficient of the n- term
product = 27 × - 2 = - 54 and sum = - 3
The factors are - 9 and + 6
Use these factors to split the n- term
27n² - 9n + 6n - 2 = 0 ( factor the first/second and third/fourth terms )
9n(3n - 1) + 2(3n - 1) = 0 ← factor out (3n - 1) from each term
(3n - 1)(9n + 2) = 0
Equate each factor to zero and solve for n
3n - 1 = 0 ⇒ 3n = 1 ⇒ n =
9n + 2 = 0 ⇒ 9n = - 2 ⇒ n = -
Answer:
<u>800 liters</u> of 90% saline solution and <u>1200 liters</u> of 40% saline solution should be used.
Step-by-step explanation:
Given:
At 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution.
Now, to find the number of liters of saline solution each should be used.
<u><em>Let the liters of 90% saline solution mix be </em></u><u><em /></u>
<u><em>And let the liters of 40% saline solution mix be</em></u>
So, the total number of liters:
Now, the total percentage of saline solution:
Substituting the value of from equation (1) we get:
Subtracting both sides by 800 we get:
Dividing both sides by 0.5 we get:
<u>The liters of 90% saline solution mix = 800.</u>
Now, substituting the value of in equation (1) to get the liters of 40% saline solution:
<u>Thus, the liters of 40% saline solution = 1200.</u>
Therefore, 800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.