+26400 find two numbers whose sum is 138 and whose difference is 88
$$\\
\small{\text{ number }} 1 = \frac{sum+difference}{2} = \frac{138+88}{2} = 113\\\\
\small{\text{ number }} 2 = \frac{sum-difference}{2} = \frac{138-88}{2} = 25\\\\
\small{\text{ number }} 1 +\small{\text{ number }} 2 = 113 + 25 = 138 \small{\text{ okay }} \\
\small{\text{ number }} 1 -\small{\text{ number }} 2 = 113 - 25 = 88\small{\text{ okay }}$$
+26400 find two numbers whose sum is 138 and whose difference is 88
$$\\
\small{\text{ number }} 1 = \frac{sum+difference}{2} = \frac{138+88}{2} = 113\\\\
\small{\text{ number }} 2 = \frac{sum-difference}{2} = \frac{138-88}{2} = 25\\\\
\small{\text{ number }} 1 +\small{\text{ number }} 2 = 113 + 25 = 138 \small{\text{ okay }} \\
\small{\text{ number }} 1 -\small{\text{ number }} 2 = 113 - 25 = 88\small{\text{ okay }}$$
