Answer:
Step-by-step explanation:
Answer:
195 mL of the 90% solution
Step-by-step explanation:
Let the number of mL of 90% mixture = x
Hence, our equation is
780mL × 15% + x mL × 90% = (780mL + x) 30%
117 + 0.9x = 234 + 0.3x
Collect like terms
0.9x - 0.3x = 234 - 117
0.6x = 117
x = 117/0.6
x = 195 mL
Therefore, You will need 195 mL of the 90% solution
Answer:
c
Step-by-step explanation: since i helped can i have brainlist please :D
Answer:
A
Step-by-step explanation:
5 and 7 are both common factors of 35 and 40
Looking at the options you can eliminate C and D right away because 7 times 8 = 56 and not 40 like the problem is asking.
This leaves A and B. Looking at the equation the difference between the two are the + and -
Using the original equation (35x-40) as reference we see that it subtracts the two variables. Therefore leaving A as the answer