Heath needs to end up with 10L of solution,
of which 9L is bleach. So let m = liters of 20%
solution needed. Then .20m liters of that are bleach.
He must then add p liters of bleach to make
a total of 10 L. That is, p + m = 10. So the system is
m + p = 10, .20m + p = 9. Solving,
<span>m = 1.25 L 20% solution, and thus p = 8.75 L bleach.</span>
You would use distribution. So, in this case, it would be 10a - 50. You use -10 to multiply -a and 5, and you get 10a, and -50.
Given the movement of Dolphin has been modeled by the function:
h(t)=-16t^2+26t
the time taken for Dolphin to reach 5 feet will be:
5=-16t^2+26t
writing the above in quadratic form ax^2+bx+c=0 we get:
16t^2-26t+5=0
solving the quadratic equation using quadratic formula we obtain:
t=13/16+/-√89/16
t=0.22 sec or 1.40 sec
You get everything you need from factoring the last expression:

The left side is a difference of squares, and we get another difference of squares upon factoring. We end up with

Plug in everything you know and solve for
:
