These are vertical angles, meaning they're always the same length.
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Let V, be the rate in still water and let C = rate river current
If the boat is going :
upstream, its rate is V-C and if going
downstream, its rate is V+C,
But V = 5C, then
Upstream Rate: 5C - C = 4 C
Downstream rate: 5C+C = 6C
Time = distance/Rate, (or time = distance/speed) , then:
Upstream time 12/4C and
Downstream time: 12/.6C
Upstream time +downstream time:= 2h30 ' then:
12/4C + 12/.6C = 2.5 hours
3/C + 2/C = 5/2 (2.5 h = 5/2)
Reduce to same denominator :
5C = 10 and Rate of the current = 2 mi/h
x + y = 4,000
0.1x + 0.04y = 352
Product A represents x and product B represents y. The first equation is the total number of items the store owner buys. The second equation is cost per item for both products. The above system of equations can be used to determine how much product A and product B the store owner bought.
0.5*2=1
Explanation: 0.5+0.5 =1