Question 328334
 let width be x
length =y
2(x+y)=68
divide by 2 both sides
x+y=34-------------------1
..
2*((x+2)+(2y+10)=100
divide by 2
x+2+2y+10=50
x+2y+12=50
x+2y=50-12
x+2y=38-----------------2
Subtract equation 1 from 2
x+2y-x-y=38-34
y=4..
x+y=34
plug the value of y 
x+4=34
x=30
The dimensions of original rectangle are 30cm by 4cm