$12 for 15 milliliters $8 for 10 milliliters yes or no

The correct answer is A. 167 milliliters of 7% solution and 333 milliliters of 4% solution and here is how:

If x is the number of milliliters of the 7% saline solution and y is the number of milliliters of the 4% saline solution then add up to 500 milliliters total, so x + y = 500.

and if we do

x + y = 500

x = 500 - y

0.07x + 0.04y = 25 (substitute 500 - y for x)

0.07(500 - y) + 0.04y = 25

35 - 0.07y + 0.04y = 25

-0.03y + 35 = 25

-0.03y = -10

y = 333.333...

y = about 333

x = 500 - y = 500 - 333 = 167

Then you know why the answer is A.

Step-by-step explanation:

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!