The midpoint of the line joining Y(2a, 3) and Z(b, -5) is (1, -1). Find the value of a and b.

Here are the solutions to the problems:

1. The midpoint of the line joining $Y(2a, 3)$ and $Z(b, -5)$ is $(1, -1)$.

a) The value of $a$ and $b$
Let the midpoint be $M(x_m, y_m) = (1, -1)$.
The coordinates of $Y$ are $(x_1, y_1) = (2a, 3)$.
The coordinates of $Z$ are $(x_2, y_2) = (b, -5)$.

Using the midpoint formula:
$x_m = \frac{x_1 + x_2}{2}$
$1 = \frac