Solve the system of equations below by graphing them. what are the ordered pairs (u, b)?

u = -b + 21

u = -2b + 30

2 Answers

Relevance
  • 10 years ago
    Best Answer

    u = -b + 21

    u = -2b + 30

    Check it out - both equations are solved for "u" already. Thus,

    -b + 21 = -2b + 30

    -b + 2b = 30 - 21

    b = 9.

    u = -b + 21 = -(9) + 21 = 12

    u = -2b + 30 = -2(9) + 30 = 12

    So, the ordered pair is (12,9).

    Source(s): :)
  • 10 years ago

    Subtract those two equations:

    0 = b - 9

    b = 9

    Substitute that into the first equation:

    u = -9 + 21

    u = 12

    I'd think the ordered pairs would be (b,u), but if you want (u,b), it's (12,9).

Still have questions? Get your answers by asking now.