The problem is 3+6x = 15 with x being the number of white numbers.
Isolate variable by subtracting 3 on both sides: 6x = 12.
Isolate variable by dividing 6 on both sides: x = 2
The number of white marbles is 2.
Answer:
D) commutative property of addition
Can you show the full screen ?
In the first step when the student did -2x-3 they didn’t make the sign positive. It should be 4=-2+6, not 4=-2-6
