Factory A produced I2 500 T-shirts this June, and 14 650 T-shirts this

July. This June and July, Factory A produced 4 500 T-shirts more
than 3/4 of T-shirts that Factory A produced last June and July.
What is quantity of T-shirts that Factory A produced last June and
last July altogether?

This year: 12500+14650 = 27150

So if they produced x last year,
27150 = 3/4 x + 4500
so now just solve for x