Answer:
They bought 6 vanilla wafers and 21 chocolate, they add up to 27.
x = amount of vanilla wafers
y = amount of chocolate wafers.
4x+y = 45
x+y= 27
Explanation:
x = amount of vanilla wafers
y = amount of chocolate wafers
Vanilla wafers = 4$ each
Chocolate wafers = 1$ each.
So, 4x+y = 45 and x+y= 27 because they spent 47$ on 27 packs.
With both equations we can substitute.
1. Change one equation so one variable is on one side
x+y = 27 to y = 27-x
2. Substitute the variable from the other equation.
4x+y = 45 to 4x+27-x = 45
3. Solve the equation for x.
4x+27-x = 45
3x+27 = 45
3x = 18
x = 6 (amount of vanilla wafers)
4. substitute with equation.
y = 27-x to y = 27-6
5. Solve the equation for y.
y = 27-6
y = 21 (amount of chocolate wafers)