Multiply each term in the first set of parentheses by each term in the second set, then combine like terms.
7x x 3x^2 = 21x^3
7x x -4x = -28x^2
7x x 5 + 35x
-6 x 3x^2 = -18x ^2
-6 x -4x = 24x
-6 x 5 = -30
Combine like terms to get:
21x^3 - 46x^2 + 59x - 30
Answer:
343,000
Step-by-step explanation:
Imagine there are a bunch of zeros to the right of the thousandths decimal place. If the 10 is raised to the fifth power, you want to move the decimal place to the right 5 times. This makes the new number 343,000. Since there are only 3 sig figs in the original number, there would be no decimal place in the standard form.
<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.
Source:
http://1728.org/mixture.htm
