Explain witch situation will give you the best price : a discount of 15% and then 10% and then 15% off that amount ,or a discount of 25%

First one:

a discount of 15% and then 10% and then 15% off that amount

Step-by-step explanation:

15% discount means 100-15 = 85% is to be paid

10% discount means 100-10 = 90% is to be paid

25% discount means 100-25 = 75% is to be paid

Let X be the cost before discount

1st offer:

85% of 90% of 85% of X

(85/100) × (90/100) × (85/100) × X

= 0.65025X

2nd offer:

75% of X

(75/100) × X

= 0.75X

Since 0.65025 < 0.75,

Offer 1 is better

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this