If x is the amount that Tanya paid for each item, then Tony's items would be x-2.25. So:
3x=4(x-2.25)
3x=4x-9
x=9
x-2.25=6.75
Tanya spent $9 on each item; Tony spent $6.75 on each of his items
Hope it helps.....................
Let w=width
L= length
3w+1=l
Perimeter -2(l+w)
2(W+3w+1)=42
Divide both sides by 2
W+3w+1=21
Subtract 1
W+3w=20
Add like terms
4w=20
Divide both sides by 4
W=5
The width is 5 inches
3w+1=l
Input the width into the equation
3(5)+1=l
15+1=l
16=l
The length of the rectangle is 16 inches
The rectangle is 5 x 16 inches