To write an equation in standard form, you need to rearrange the terms so that the variables are on one side of the equal sign and the constants are on the other side. The standard form of a linear equation is typically written as Ax + By = C, where A and B are constants and x and y are variables.
The given equation y = 2/3x + 7 can be written in standard form by moving all of the terms containing x to the left side of the equal sign and all of the constants to the right side:
2/3x - y = -7
Multiplying both sides of the equation by 3 and simplifying, we get:
3(2/3x - y) = 3(-7)
2x - 3y = -21
Therefore, the equation y = 2/3x + 7 can be written in standard form as -2x - 3y = -21, which corresponds to answer choice (D).