Practice problem
Which of these is/are equivalent to 9+b+x9+b+x9+b+x?
x+(9+b)x+(9+b)x+(9+b)
9+x+b9+x+b9+x+b
3×3b+x3\times3b+x3×3b+x
b+x+9b+x+9b+x+9
x+3×3+bx+3\times3+bx+3×3+b
Type a concept, like “slope” or “photosynthesis”.