Factor by grouping.
(7x+2)(x-2) I think not sure
Answer:
160
Step-by-step explanation:
Step-by-step explanation:
<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
Answer:
t≤ 9
Step-by-step explanation:
3.5+4t≤ 39.5
subtract 3.5 from each side
4t≤ 36
divide each side by 4
t≤ 9
