Answer:
CN Tower = 550 m and church tower = 160 m
Step-by-step explanation:
The first equation x + y = 710 is correct
but the second one is
x - y = 390
Note x = height of the CN tower and y = height of the church.
x + y = 710
x - y = 390
If we add the 2 above equations we eliminate y so
2x = 1100
x = 550 m
and y = 710 - 550 = 160 m