Answer:
Step-by-step explanation:
1) Eliminate parentheses:
0.1x +18.8 = -4 +2x
22.8 = 1.9x . . . . . . . . . add 4 - 0.1x
12 = x . . . . . . . . . . . . . divide by 1.9
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2) Eliminate parentheses:
-16 +4x = 0.8x +12.8
3.2x = 28.8 . . . . . . . . add 16 - 0.8x
x = 9 . . . . . . . . . . . . . .divide by 3.2
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<em>Comments on the solutions</em>
The expression we add in each case eliminates the constant on one side of the equation and the variable term on the other side. That leaves an equation of the form ...
variable term = constant
We choose to eliminate the smaller variable term (the one with the coefficient farthest to the left on the number line). Then the constant we eliminate is the on on the other side of the equation. This choice ensures that the remaining variable term has a positive coefficient, tending to reduce errors.
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You can work these problems by methods that eliminate fractions. Here, the fractions are decimal values, so are not that difficult to deal with. In any event, it is good to be able to work with numbers in any form: fractions, decimals, integers. It can save some steps.
Let x be the number of days.
Daily pass:
65x + 30x
95x
Season pass:
400 + 30x
95x > 400 + 30x
65x > 400
x > 6.15
The number of days can't be 6.15, so you must round. You can't go down because then the price will be more expensive, so you have to round up.
It would take 7 days until the season pass is less expensive than the daily pass.
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You can check this by plugging in the x.
95x > 400 + 30x
95(7) > 400 + 30(7)
665 > 400 + 210
665 > 600
The daily pass is more expensive than the season pass.
This is true because the answer is -6 = -6
I think the answer is the Last one
