Answer: 64 pounds of type B coffee she used
Explanation:
Let the number of pounds of type A coffee she used - x
and the number of pounds of type B coffee she used - y
Hence,
x+y=161
4.10(x)+5.40(y)=743.30
4.10x+4.10y+1.3y=743.30
4.10(x+y)+1.3y=743.30
4.10(161)+1.3y=743.30
660.1+1.3y=743.30
660.1+1.3y-660.1=743.30-660.1
1.3y=83.2
Divide both parts of the equation by 1.3:
y=64 pounds