2X+0.5X=22.5
2.5 times =22.5
X=22.5÷2.5
x=9
A: One adult ticket, 9 yuan.
(1)38.7x2=77.4 yuan
(2) 38.7x0,7x3 = 81.27 yuan.
77.4 yuan < 8 1.27 yuan
Star bakery is cheaper.