Answer:
The cost of a rice cooker = $50
Explanation:
Williams sold 5 oven toasters and 3 rice cookers for $500.
let
cost of an oven toaster = a
cost of a rice cooker = b
5a + 3b = 500 ............(i)
A rice cooker cost $20 less than an oven toaster.
a - b = 20...........(ii)
a = 20 + b
insert the value of a in equation (i)
5a + 3b = 500 ............(i)
5(20 + b) + 3b = 500
100 + 5b + 3b = 500
100 + 8b = 500
8b = 500 - 100
8b = 400
divide both sides by 8
b = 400/8
b = 50
insert b in equation (ii)
a - b = 20...........(ii)
a - 50 = 20
a = 50 + 20
a = 70