1. Problem: Given midpoint M(3,4) and point A(5,7), find coordinates of point B. 2. Formula: Midpoint M of segment AB is given by $$M=\left(\frac{x_A+x_B}{2}, \frac{y_A+y_B}{2}\right)$$. 3. Using the formula, set up equations: $$3=\frac{5+x_B}{2}, \quad 4=\frac{7+y_B}{2}$$ 4. Multiply both sides by 2: $$6=5+x_B, \quad 8=7+y_B$$ 5. Solve for $x_B$ and $y_B$: $$x_B=6-5=1, \quad y_B=8-7=1$$ 6. Therefore, coordinates of B are $(1,1)$. Final answer: B(1,1)