Liam's bookstore sold 40 notebooks and 20 newspapers for a total of $130.
A day later, the bookstore sold 8 notebooks and 4 newspapers at the same prices, for a total of $28.
How much does a notebook and a newspaper cost at Liam's bookstore?
let x = price of 1 notebook ($) let y = price of 1 newspaper ($) Solving method : Elimination 1st step : write the system of equation 40x + 20y = 130 8x + 4y = 28
2nd step : make the variables equal to each other -5(8x + 4y ) =( 28)(-5) -40x - 20y = -140 3rd step : add the equations 40x + 20y = 130 + -40x - 20y = -140 ___________________ 0 = -10
