We can use these variables:
A = number of ounces for solution A
B = Number of ounces for solution B
A + B = 20
Now, we can use decimal conversions.
0.65A + 0.80B = 0.70(120)
Next step: We substitute A into 120 - B to show their relationship.
0.65(120 - B) + 0.80B = 84
Now onto the next equation:
78 - 0.65B + 0.80B = 84
0.80 - 0.65 = 0.15, so…
0.15B = 84 - 78
0.15B = 6
B = 6 divided by 0.15
B = 40 ounces
To find A, we can simply plug B into the starting equation.
A = 120 - 40
A = 60 ounces
Your final answer: The scientist should use 60 ounces of solution A and she should use 40 ounces of solution B. Yeah
Answer:
3.9
Step-by-step explanation:
2p-9.9
=2(3)-9.9
=6-9.9
=-3.9
Formula used: cos(x) = 
Hope this helped!
~Just a girl in love with Shawn Mendes