Hi!
This problem uses a two equation system(I don't know the proper name).
First, we "turn words into math" as some people call it.
Let x = Type A Coffee
Let y = Type B Coffee
If he made 177 pounds, then the following must be true:
x + y = 177
Also, if Type A Coffee costs $4.30 a pound, and Type B Coffee costs $5.70 a pound, then the following also must be true:
4.30x + 5.70y = 877.30
Now, we make some like terms and combine the equations:
If we multiply the first equation by 4.3:
4.30x + 4.30y = 761.10
And now we subtract the second equation from the first:
4.30x + 4.30y = 761.10
4.30x + 5.70y = 877.30
-1.40y = -116.2
Divide by -1.40:
y = 83.
y equals the number of pounds of type b coffee, so we subtract 83 from 177.
I think you can do the rest yourself. :)
Hope this helps!