One number is 7 less than another. The product of the numbers is 44. Find the numbers.
well let x be one number, so the other number is x - 7 so x(x-7) = 44 which is \[x^2 - 7x - 44 = 0\] just solve the quadratic for the solutions
x(x-7)=44 x^2-7x-44=0 (x-11)(x+4)=0 I got X=11, -4 but my teacher said there was 4 answers
well thats not strictly correct as the 2nd number is dependent on the 1st... so there are 2 unique 1st numbers.... and the 2nd number depends on the 1st. the other method let x be the smaller number... so the larger number is x + 7 so x(x + 7) = 44 or \[x^2 + 7x - 44 = 0\]
Would they be (11,4) and (-4,11)?
so the solutions are 11 and 4 -4 and - 11
Gratzi!
Would there always be 2 solutions to this type of problem or just depending on the numbers?
well a quadratic always has 2 solutions... they may be equal... as in a perfect square... or complex... or real... but always 2
mkay, thanks.
Join our real-time social learning platform and learn together with your friends!