Last year Emily invested some money and had gained 8% profit and her friend, Samira invested some money and gained 9% profit. Their total profit on the two investments was $1720. This year they each decided to invest the same amount of money as last year. Emily gained 7% profit this year and Samira gained 6%. If they receive a total profit of $1280, how much money did Emily invest? Answer.

step-by-step explanation:

it is a secret for it not to be compromised sorry

step-by-step explanation:

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0