The perimeter of a rectangle is 64 m and its length is 3 times its width, what is the length of the Rectangle?

Length = 24m

Step-by-step explanation:

Perimeter = 2(length + width)

then:

p = 2(e+w)   eq.1

e = 3w     eq. 2

Replacing the eq. 2 in the eq. 1

64 = 2(3w+w)

64 = 2(4w)

64 = 8w

64/8 = w

w = 8

from the eq. 2

e = 3*8

e = 24

Check:

from the eq. 1

64 = 2(24+8)

64 = 2*32

idc

step-by-step explanation:

idk

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.