Geometry/algebra problem HELP?

sara-marysara-mary
in Science & Mathematics

if Ris the midpoint of line ST, SR=3x-2 and ST=5x+3, calculate RT

PLEASE EXPLAIN ANSWER! And make it Nice so I could understand it! Thank you(:

Comments

  • mr-coolmr-cool

    If R is the midpoint, then SR is one-half of the line segment ST. Therefore:

    3x-2 = (5x+3)/2

    2(3x - 2) = 5x + 3

    6x - 4 = 5x + 3

    x - 4 = 3

    x = 7

    Since R is the midpoint, SR and RT are the same length. Since the length of SR is 3x-2, that is also true for segment RT. Plug in 7 for x to solve for the length:

    RT = 3x - 2

    RT = 3(7) - 2

    RT = 21 - 2

    RT = 19

    Segment RT is 19 units long.

  • pinkgreenpinkgreen

    ST=SR+RT=>

    5x+3=3x-2+RT=>

    RT=5x+3-3x+2=>

    RT=2x+5

  • shane-parksshane-parks

    so what you want to do, since SR is only part of ST, you want to subtract SR from ST giving you:

    ST=SR+RT

    5x+3=3x-2+(RT)

    -3x -3x

    2x+3=-2+(RT)

    +2 +2

    2x+5=(RT)

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