Answer:
x= -19
y= -14
Step-by-step explanation:
Substitution.
It tells you what y is already. You substitute that into the second equation and then solve. Then you use that answer and substitute it back into the first equation's x, and then you'll get your full answer.
Hope this helps <3
Y = -3x + b
Plug in point
-4 = -3(3) + b
-4 = -9 + b, b = 5
Solution: y = -3x + 5
Two cheaper books = x
more expensive = 1.5x
so, 2.5x=150
150/2.5=x=60
therefore the more expensive book = 90