x is the independent variable, and in this scenario, the independent variable is the number of days overdue. So the best equation would be where x is the number of days overdue, and y is the cost in cents.
Example equation:
x = number of days overdue
y = cost in cents
z = total price
z = yx
2(2x) + 1x = 40 or 4x + 1x = 40 is the result of combining by substitution
<em><u>Solution:</u></em>
Given that we have to combine 2y + 1x = 40 and y = 2x using substitution method
The substitution method for solving systems of equations involves expressing one variable in terms of another, thus removing one variable from an equation.
<em><u>Given equations are:</u></em>
2y + 1x = 40 -------- eqn 1
y = 2x ----------- eqn 2
We can substitute eqn 2 in eqn 1
Which means, substitute y = 2x in place of y in eqn 1
2(2x) + 1x = 40
4x + 1x = 40
5x = 40
x = 8
From eqn 2,
y = 2(8)
y = 16
Thus by combining using substitution method we found the solution
