SOLUTION: I have a world problem, not sure if I came up with the right answer. Could I have some help on this, thanks. The good seed flower shop sells its own brand of fertilizer. It mixes o

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Question 130391: I have a world problem, not sure if I came up with the right answer. Could I have some help on this, thanks. The good seed flower shop sells its own brand of fertilizer. It mixes one brand of fertilizer that contains 7% nitrogen with another that contains 8% nitrogen. The resulting mixture contains 7.7% nitrogen. How many pounds of the 8% fertilizer must be used to make 200 pounds of the 7.7% mixture? I have 98.6 Could you let me know if it is correct. Thank you, I appreciate the help.
Found 2 solutions by checkley71, scott8148:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
.08X+.07(200-X)=.077*200
.08X+14-.07X=15.4
.01X=15.4-14
.01X=1.4
X=1.4/.01
X=140 POUNDS OF 8% FERTILIZER IS NEEDED.
200-140=60 POUNDS OF 7% IS NEEDED.
PROOF:
.08*140+.07*60=.077*200
11.2+4.2=15.4
15.4=15.4

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
since 7.7 is closer to 8 than to 7, there must be more of the 8% (more than 100lb)

let x="pounds of 8%", so 200-x="pounds of 7%"

(8%)(x)+(7%)(200-x)=(7.7%)(200) __ .08x+14-.07x=15.4 __ .01x=1.4