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raddmadd
raddmadd asked in Science & MathematicsMathematics · 10 years ago

Joint variation math problem?

T varies jointly as X and E2. When X=2, E=2, T=40. Find T when X is 7 and E is 8. The E is squared. I arrived at: T = 2240. Can you guys break the process down and tell me if I'm correct? Thanks!

Update:

Thanks guys, since you all answered similarly I will choose the first one.

3 Answers

Relevance
  • ?
    Lv 6
    10 years ago
    Favourite answer

    T proportional to X*E^2

    T=k*X*E^2

    case 1:

    40=k*2*4

    k=5

    case 2:

    T=5*7*64=2240

  • Como
    Lv 7
    10 years ago

    T = k X E ²

    k = T / ( X E² ) = 40 / ( 2 x 4 ) = 5

    T = 5 (7) (64)

    T = 2240

  • Ed I
    Lv 7
    10 years ago

    T = kXE^2

    40 = k(2)(2^2) = 8k

    k = 5

    T = 5XE^2

    T = 5(7)(8^2) = 2240

    I agree with you.

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