If y = 2x + 3, what is y when x = 0?

If y = 2x + 3, what is y when x = 0?

• A. y = 0
• B. y = 6
• C. y = 3
• D. y = -3

Answer: (C)

Plug in x into the equation y = 2x + 3. With x = 0, y = 2(0) + 3 = 3. So the value is 3. This also matches the y-intercept of the line. The other numbers would require different x-values (for example, y = 0 would need x = -3/2, y = 6 would need x = 3/2, and y = -3 would need x = -3), which isn’t the case when x is zero.

Plug in x into the equation y = 2x + 3. With x = 0, y = 2(0) + 3 = 3. So the value is 3. This also matches the y-intercept of the line. The other numbers would require different x-values (for example, y = 0 would need x = -3/2, y = 6 would need x = 3/2, and y = -3 would need x = -3), which isn’t the case when x is zero.