Final answer:
To find the equivalent expression to 7x√2 - 4√2 + x√2, like terms are combined, resulting in 8x√2 - 4√2, which is option D.
Step-by-step explanation:
The student's question is asking to find an expression equivalent to 7x√2 - 4√2 + x√2. To solve this, we need to combine like terms. Both 7x√2 and x√2 have the same radical and variable part, so they can be added together. This results in 8x√2. The term -4√2 does not have a variable part, so it stands alone. Therefore, the equivalent expression is 8x√2 - 4√2, which corresponds to option D.