Answer:
24
Explanation:
Opposite sides on a rectangle are equal
So 2(3x+3)+2(4x)=104
Now expand, so 6x+6+8x=104
Simplify like terms, 14x+6=104
14x+6-6=104-6
14x=98
14x/14=98/14
x=7
Now just substitute the 7 in for the 3x+3 as thats what we are looking for.
3×7+3=24