(4,?) is on the line y=2x+3. Find the other half of the coordinate

well, x is 4, so just substitute 4 for x and evaluate, to get y.

y = 2*4+3

To find the missing coordinate, we can substitute the given x-value into the equation of the line and solve for y.

Given:
Point (4, ?)
Line equation: y = 2x + 3

Substituting x = 4 into the line equation:
y = 2(4) + 3
y = 8 + 3
y = 11

Therefore, the other half of the coordinate is (4, 11).