640-110•(90:18)

To solve the equation 640-110•(90:18), first perform the division inside the parentheses:

90:18 = 5

Now substitute the result back into the equation:

640 - 110 • 5

Next, perform the multiplication:

110 • 5 = 550

Now substitute the result back into the equation:

640 - 550

Finally, subtract:

640 - 550 = 90

Therefore, the solution to the equation 640-110•(90:18) is 90.