Answer:
Step-by-step explanation:
let : x the length and y the width .... ( x > y and x ; y reals numbers )
the perimeter is : 2(x+y)
2(x+y) = 55...(1)
x/y = 7/4 ...(2)
by (2) : x = (7/4)y
subsct in (1) : 2( (7/4)y +y ) =55
(7/2)y +2y =55
multiply by 2
7y +4y = 110
11y = 110
y = 10
x = (7/4)(10)
x = 35/2
9 + (3 x 4) - 6 + 12/3 3 makes 12 4 times which is why 12/3 is 4
9 + 12. -6. +. 4
21 - 6 + 4
15+4 = 20
