Answer:
another example
Step-by-step explanation:
Let x represent number of novels and y represent number of magazines.
If Sadie purchased a total of 11 novels and magazines,
x + y = 11 ----- eqn(1)
Each novel sells for $4 thus, if Sadie purchased x novels, she will spend $4x
Each magazines sells for $1, thus, if Sadie purchased y magazines, she will spend $1y or $y
The combined selling price for 11 novels and magazines is $20
4x + y = 20 ------- eqn(2)
from eqn(1),
y = 11 - x ----- eqn(3)
Substitute eqn(3) into eqn(2)
4x + 11 - x = 20
3x = 20 - 11
3x = 9
x = 9/3
x = 3
Sadie purchased 3 novels