Answer:
3x + 2y = 315 -----(1)
2x + 4y = 450 -----(2)
from (1) 3x + 2y = 315
2y = 315-3x
y = 157.5 - 3/2x ---- (3)
substitute (3) into (2)
2x + 4y = 450
2x + 4(157.5 - 3/2x ) = 450
2x + 630 - 6x = 450
-4x = -180
x = 45 ---- (4)
substitute (4) into (3)
y = 157.5 - 3/2x
y = 157.5 - 3/2(45)
y = 90
a haircut,x = 45 minutes
dye hair,y = 90 minutes
