For this case we have to:
x: Variable that represents Tyler's age
y: Variable that represents Tiffany's age
According to the data of the statement we can propose the following equations:
![x = y + 4\\x + 10 = 2y](https://img.qammunity.org/2021/formulas/mathematics/high-school/xhv954obms9c7oimwdozvbudrhc9uxojyc.png)
To solve we substitute the first equation in the second equation:
![y + 4 + 10 = 2y\\14 = 2y-y\\14 = y](https://img.qammunity.org/2021/formulas/mathematics/high-school/wed00euyde8owa18yphtq7nuet9nyotooe.png)
So, Tiffany is 14 years old.
Then Tyler has:
![x = 14 + 4\\x = 18](https://img.qammunity.org/2021/formulas/mathematics/high-school/m5eofpswgc0i4d4ptgbovuv16wf4oj31ub.png)
Tyler is 18 years old.
Answer:
Tyler: 18 years old
Tiffany: 14 years old