Answer:

Step-by-step explanation:
We have the following quadratic equation

The factored expression will have the following form

Where b and c are two real numbers which when added together result in -1, and multiplying them results in -20

You can verify that the numbers that meet this condition are:
-5 and 4
Then the factors are:

84 pounds of Type B coffee is used
<em><u>Solution:</u></em>
Let "x" be the pounds of type A coffee
Let "y" be the pounds of type B coffee
Cost per pound of type A = $ 5.50
Cost per pound of Type B = $ 4.20
<em><u>This month, Chau made 143 pounds of the blend</u></em>
x + y = 143
x = 143 - y -------- eqn 1
<em><u>For a total cost of $677.30. Thus we frame a equation as:</u></em>
pounds of type A coffee x Cost per pound of type A + pounds of type B coffee x Cost per pound of Type B = 677.30

<em><u>Let us solve eqn 1 and eqn 2</u></em>
<em><u>Substitute eqn 1 in eqn 2</u></em>

Thus 84 pounds of Type B coffee is used
Answer:
I'm pretty sure it is 7.4% or 0.074.
Step-by-step explanation: