Algebra Problem

[12345786332]

I found 25^2 = 35^2 + x^2 - 70cos(20)x, but my isolation of the x variable did not align with x^2 - kx + 600 = 0

 

[Deleted member 4993]

View attachment 24642

I found 25^2 = 35^2 + x^2 - 70cos(20)x, but my isolation of the x variable did not align with x^2 - kx + 600 = 0

Please show how do you claim ".... did not align with x^2 - kx + 600 = 0"

 

[12345786332]

Please show how do you claim "... did not align with .x^2 - kx + 600 = 0" .................................[edited]

That's part of the question.

 

[Steven G]

I disagree with your statement at the end.
a^2 - b^2 = (a+b)(a-b)
So 35^2 - 25^2 = (35+25)(35-25)=60*10=600

 

[Steven G]

One of the reasoning the posting guidelines ask that you share your work (not just part of it) is so we can see where you made a mistake.

 

[Steven G]

I am baffled at why you are asking for help after arriving at 25^2 = 35^2 + x^2 - 70cos(20)x

0 =x^2 - 70(cos20)x + (35^2-25^2) = x^2 -70cos20*x + 600. k = 70cos(20). Just calculate it and be done.