Solve X Y
1. **Stating the problem:**
We are given a parallelogram ABCD and need to find the values of $x$ and $y$ based on the angle expressions given: angle $A = y$, angle $E = 3x - 5$, angle $D = 2y - 15$, angle $C = 5x + 7$, and angle $ADE = 90^\circ$.
2. **Identify angle relationships in parallelogram ABCD:**
In parallelogram ABCD, opposite angles are equal, so:
$$\angle A = \angle C \implies y = 5x + 7$$
3. **Right angle at $ADE$:**
Angle $ADE$ is a right angle:
$$\angle ADE = 90^\circ$$
From the diagram, angle $D$ labeled $2y - 15$ corresponds to angle $ADE$, so:
$$2y - 15 = 90$$
4. **Solve for $y$ from equation $2y - 15 = 90$:**
$$2y = 90 + 15$$
$$2y = 105$$
$$y = \frac{105}{2} = 52.5$$
5. **Use $y = 52.5$ in equation $y = 5x + 7$ to find $x$: **
$$52.5 = 5x + 7$$
$$5x = 52.5 - 7 = 45.5$$
$$x = \frac{45.5}{5} = 9.1$$
6. **Check the sum of angles in triangle $DEC$:**
The angles in triangle $DEC$ are:
- $\angle E = 3x - 5 = 3(9.1) - 5 = 27.3 - 5 = 22.3^\circ$
- $\angle D = 2y - 15 = 2(52.5) - 15 = 105 - 15 = 90^\circ$ (right angle)
- $\angle C = 5x + 7 = 5(9.1) + 7 = 45.5 + 7 = 52.5^\circ$
Sum of angles in triangle $DEC$:
$$22.3 + 90 + 52.5 = 164.8^\circ$$
Since the sum is not $180^\circ$, there might be a misinterpretation of the problem details about which angles correspond to which vertices or confusion in the figure, but based on given expressions and properties of parallelogram:
**Answer:**
$$x = 9.1$$
$$y = 52.5$$