Figure A is a scale image of figure B. X
5
Figure A
Figure B
Figure A maps to figure B with a scale factor of 2
2 1 /

Work Shown:

2 & 1/2 = 2 + 1/2 = 2 + 0.5 = 2.5

The scale factor is 2.5

This means we multiply the scale factor by the preimage length x, to get the corresponding image length 5

In other words,

(preimage length)*(scale factor) = image length

x*2.5 = 5

2.5x = 5

x = 5/2.5 divide both sides by 2.5

x = 2

We can see this also by dividing the image length over the preimage length

scale factor = (image length)/(preimage length)

scale factor = 5/2

scale factor = 2 & 1/2

scale factor = 2.5