Inow the shape for not cubes i need explain

The bottom right, middle top, and bottom left are NOT cubes.

Step-by-step explanation:

Cubes are defined as a three dimensional object with the same length, width, and height. Since the square on the bottom left is two dimensional, It is not a cube. Since the hexagon on the bottom right is two dimensional, It can't be a cube. The Middle top shape doesn't have the same length height as it's width is, so it is not a cube. The rest are cubes.

Circle 1st, 2nd, 4th, and 6th

Step-by-step explanation:

A cube is 4 perfect squares in a 3-D shape. Only shape 3 and 5 show this.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

i did it myself and i got 4.2 (b) hope its right

step-by-step explanation: