Answer:
12mx-15m-20x+25 Hope this helps!
Step-by-step explanation:
Answer:
154.8
Step-by-step explanation:
20% is equal to 20/100= 0.20. So, 0.20 multiplied by 129 will give you 20% of 129 which is 25.8. If Alan ran 20% more then you add 25.8 to 129 which gives you an answer of 154.8.
Equation: 20/100= 0.2
0.2* 129= 25.8
25.8+129= 154.8
Alan ran 154.8 laps.
You can use a tangent:

We have opposite = 17 and adjacent = x.

substitute:
cross multiply
multiply both sides by √3

divide both sides by 3

Use the Pythagorean theorem:

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Other method.
triangle.
The sides are in the ratio 
Therefore

425 is decreased to 319.
The above statement means that a number should be deducted from 425 to get the difference of 319.
Let x be the unknown number.
425 - x = 319
425 - 319 = x
106 = x
106 is the unknown number.
It can be phrased like this: 425 decreased by 106 is 319.