Simplify 7p+2p-9p anyone know need answer asap

answer:

z^2 + (-1 + 5·i)·z + 14 - 7·i = 0

(1 + 2·i)^2 + (-1 + 5·i)·(1 + 2·i) + 14 - 7·i = 0

(1 + 4·i - 4) + (-1 - 2·i + 5·i - 10) + 14 - 7·i = 0

0 = 0 --> true

z^2 + (-1 + 5·i)·z + 14 - 7·i = 0

(1 - 2·i)^2 + (-1 + 5·i)·(1 - 2·i) + 14 - 7·i = 0

(1 - 4·i - 4) + (-1 + 2·i + 5·i + 10) + 14 - 7·i = 0

20 - 4·i = 0 --> false

answer:

x = 1,143 liters

step-by-step explanation:

to solve this problem let's pose the following equation:

(amount of peroxide added + amount initial of solution)*(% of desired peroxide/100) = (amount of initial peroxide + amount of peroxide added).

* the added amount is unknown and we will call it x

* the percentage of peroxide desired is 16%

* the amount of initial peroxide is calculated as follows:

(%peroxide/ 100)(amount of initial substance)

= 0.08(12)

finally the equation is:

(x + 12)(0.16) = 0.08(12) + x

0.16x -x = 0.96 - 1.92

-0.84x = -0.96

x = 1,143