Question 1117368
this is what i get after repeated tries to understand what they mean.


x% is equal to 100x.


if the profit is x%, then the profit is 300 * x.


for example, if x% = 10, then x = .10 and the profit is 300 * .10 = 30
30/300 = .10 * 100 = 10%.


300 + 300 * x is equal to 300 * (1 + x)


lee bought it for 300.


wong paid 300 * (1 + x).


fei paid 300 * (1 + x) * (1 + x).


that means that fei paid 300 * (1 + x)^2.


fei paid 6x + .75 more than what lee paid for it.


that means that fei paid 300 + 6x + .75.


since fei also paid 300 * (1 + x)^2, then you get:


300 * (1 + x) ^ 2 = 300 + 6x + .75


since (1 + x)^2 is equal to 1 + 2x + x^2, then:


300 * (1 + 2x + x^2) = 1 + 2x + x^2


simplify to get:


300 + 600x + 300x^2 = 300 + 6x + .75


the 300 on both sides of the equation cancel out and you are left with:


600x + 300x^2 = 6x + .75


subtract the right side of the equation from both sides of the equation to get:


594x + 300x^2 - .75 = 0


reorder the terms in descending order of degree to get:


300x^2 + 592x - .75 = 0


factor this quadratic equation to get:


x = -1.9812618221237 or x = 0.0012618221237011 


x can't be negative, so x has to be 0.0012618221237011 or there is no solution.


when x = 0.0012618221237011, 300 * (1 + x)^2 = 300.757570933 and 300 + 6x + .75 = 300.757570933


since they're the same, then the solution is good.


your solution is that x = 0.0012618221237011


x% is equal to 100 * x, therefore x% would be equal to 0.12618221237011%.


they didn't ask for x%, so go with the value of x = 0.0012618221237011.