does anyone know how to do this algebra problem?

The perimeter of a rectangle is 42m the length of the rectangle is 3 m less than twice the width. Find the length and width of the rectangle.

Comments

  • w—width:

    2(w + 2w - 3) = 42

    3w - 3 = 21

    3w = 24

    w = 8

    Length:

    = 2(8) - 3

    = 16 - 3

    = 13

    Answer: width, 8 meters; length, 13 meters

  • Perimeter = 42 m

    Width = X

    Length = 2X - 3 -- Twice (or 2 times) the width - 3m

    Perimeter of a rectangle = 2(width) + 2(length) --> Plug in everything you know

    42 = 2X + 2(2X - 3) --> Factor everything out

    42 = 2X + 4X - 6 --> Add 6 to both sides

    48 = 2X + 4X --> Add like variables together

    48 = 6X --> Divide by 6

    8 = X

    Therefore, width = 8

    To find length, plug in 8 to 2X - 3:

    2(8) - 3 = 16 - 3 = 13

    Hope that helps!

  • Let w be the width. Then the length is 2w - 3. The perimeter is the sum of all four side lengths, so:

    w + w + (2w-3) + (2w-3) = 42

    Solve this for w, which is the width. Then the length is 2w - 3.

  • This is what you know:

    P=2L+2W and P=42

    you can set the length equal to x.

    L=2x-3 and therefore, W=x

    understand that 2x-3 represents the 3m less than twice the width which is x.

    plug that into you perimeter equation:

    42=2(2x-3)+2(x) and solve for x

    42=4x-6+2x

    48=6x

    x=8

    no plug x into your W and L equations:

    W=x=8m

    L=(2x-3)=13m

    you can check your answer:

    P=2(8)+2(13)=42

  • Let width =a, then length =2a-3

    perimeter = 2(a +2a-3) = 2(3a-3) =42

    3a-3 =42/2 =21

    3a = 21+3 =24

    a =24/3 = 8 m

    length = 2a-3 = 16-3 =13 m

    width =a = 8 m

  • We know that the perimeter of a regtangle is

    P = 2l + 2w

    So just apply it to your problem.

    42 = 2(2w - 3) + 2w

    See how I got that? When I saw "twice the width," that translated to "2w." 3 less than that would be 2w - 3. That's l. Now substitute it back into your "P = 2l + 2w" and solve for w. Then go back and use that w to solve for l.

  • Length = 2 x width - 3

    so l = 2w - 3

    2l + 2w = 42

    substitue 2w - 3 for l

    2(2w - 3) + 2w = 42

    That gives you w. Double it and subtract 3 and you get length

  • L = 2W – 3

    L + W = 3W – 3 = 21

    3W = 24

    W = 8

    L = 13

  • hi buddy this an undemanding question consistent with linear equations you ought to use transposition approach in this methodology whilst a term is transfered from one area to different its sign will become opposite answer: x+4-7x=22 =4-7x=22-x (right here x comes from the left area its sign differences) =4=22-x+7x(right here 7x comes from the left area its sign differences) =4-22=6x(comparable) =-18=6x x=-18/6 =-3 Bye Bye!!!!!!!!!!!!!!!!!!!!!!

  • I know how to do it, but I would be depriving you the satisfaction (and the knowledge) of letting you learn it like you're supposed to.

    It doesn't seem relevant now, but yes you will need to know it one day.

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