Answer:
Step-by-step explanation:
%profit = selling price - cost price/cost price * 100
If Mr. Wayne marks up every item with a profit of 25% and x be his cost for a calculator, the expression for the selling price can be gotten by substituting the parameters into the formula;
25 = sp-cp/cp * 100
25/100 = sp-x/x
0.25 = sp-x/x
cross multiply
0.25x = sp-x
add x to both sides
0.25x+x = sp-x+x
1.25x = sp
selling price = 1.25x
<em>Hence an expression for the selling price of the calculator is 1.25x</em>
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b) If Mr wayne paid $25, the selling price is derived by substituing x = $25 into the expression in (a)
selling price = 1.25x
selling price = 1.25($25)
selling price = $31.25
c) If the selling price is $86, to get the cost of the calculator, substitute the selling price into the expression in (a)
selling price = 1.25x
$86= 1.25x
x is the cost price of the calculator
divide both sides by 1.25
$86/1.25= 1.25x/1.25
x = $68.8
<em>Hence Wayne paid $68.8 for a calculator that he sells for $86.</em>
