simulatenoues equation?
2008-05-15 8:12 am
a tank of petrol and a refill of oil cost 30$. the tank of petrol costs 29$ more than the refill of oil. what is thecost of each.. plz explain wid working out..
回答 (5)
2008-05-15 8:22 am
✔ 最佳答案
Let x be the cost of a tank of petrolLet y be the cost of a refill of oil
x + y = 30
x = 29 + y
29 + y + y = 30
29 + 2y = 30
2y = 1
y = 1/2
y = 0.50
x = 29 + 0.50
x = 29.50
Therefore, a tank of petrol costs 29.50 and a refill of oil costs 50 cents
2008-05-15 11:43 pm
p = petrol's costs
o = oil's costs
p + o = 30
p = o + 29
p + o = 30
o = 30 - p
p = o + 29
p = (30 - p) + 29
p = 30 - p + 29
p + p = 30 + 29
2p = 59
p = 59/2
p = 29.5
p + o = 30
29.5 + o = 30
o = 30 - 29.5
o = 0.5
A tank of petrol costs $29.5.
A refill of oil costs $0.5.
o = oil's costs
p + o = 30
p = o + 29
p + o = 30
o = 30 - p
p = o + 29
p = (30 - p) + 29
p = 30 - p + 29
p + p = 30 + 29
2p = 59
p = 59/2
p = 29.5
p + o = 30
29.5 + o = 30
o = 30 - 29.5
o = 0.5
A tank of petrol costs $29.5.
A refill of oil costs $0.5.
2008-05-15 3:55 pm
let o = the cost of a refill of oil
let p = the cost of a tank of petrol
1. set up the two simultaneous equations
o + p = 30
p = o + 29
use the substitution method to solve the equations
o + p = 30
o + (o+29) = 30
2o + 29 = 30
2o = 1
o = 0.5
o + p = 30
p + 0.5 = 30
p = 29.50
let p = the cost of a tank of petrol
1. set up the two simultaneous equations
o + p = 30
p = o + 29
use the substitution method to solve the equations
o + p = 30
o + (o+29) = 30
2o + 29 = 30
2o = 1
o = 0.5
o + p = 30
p + 0.5 = 30
p = 29.50
2008-05-15 3:22 pm
p + o = $30
p = o + $29
(o+29) + o = 30
2o + 29 = 30
o = 0.50
p = 29.50
petrol cost $29.50, oil cost $0.50
p = o + $29
(o+29) + o = 30
2o + 29 = 30
o = 0.50
p = 29.50
petrol cost $29.50, oil cost $0.50
2008-05-15 3:20 pm
p = cost of tank of petrol
o = cost of an oil refill
we know o + p = 30 and p = o + 29
substitute the latter into the first to get
o + (o + 29) = 30
2o = 1
o = $.5
plug that into either equation...
p = .5 + 29 = $29.5
o = cost of an oil refill
we know o + p = 30 and p = o + 29
substitute the latter into the first to get
o + (o + 29) = 30
2o = 1
o = $.5
plug that into either equation...
p = .5 + 29 = $29.5
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