Which expression is equivalent to ........? 6.52 – 6. 7(3+6) A. (60)2 · 7(9) B. 6(10)2 - 21 +42 C.6(25)+ 7(9) D. 150 - 21-42
1 answer:
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Answer:
4:1 (I think)
Step-by-step explanation:
Let's write some equations first:
For both prices increasing by 20:
then we can use cross multiplication
2x+40=5y+100
For both prices decreasing by 5:
same here:
5y-25=x-5
Using substitution for 5y, we get: 5y=x+20
2x+40=5y+100
2x+40=x+20+100
x=80
plugging this in to the second equation:
5y-25=x-5
5y-25=80-5
5y-25=75
5y=100
y=20
therefore we get x:y=80:20
4:1