Answer:
x = 9/2
Step-by-step explanation:
Let the left-most figure be Figure A.
Let the right-most figure be Figure B.
Figure A area:
10 cm * x cm = 10x cm squared
Figure B area:
(3 cm + x cm) * 6 cm = 18 cm + 6x cm
Create the equation:
10x = 18 + 6x
Solve:
10x = 18 + 6x
4x = 18
x = 18/4
x = 9/2
