The cost of a pen is x cents and the cost of a ruler is y cents. 2 pens and 3 rulers have a total cost of 57 cents. 5 pens and 1 ruler have a total cost of 58 cents. Find the value of x and the value of y showing the process how you arrived at those answers.
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Math problem solution help
- Thread starter Gureni
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Total cost of 2 pens and 3 rulers :2x+3y=57 cents - eq 1
cost of 5 pens and 1 ruler : 5x+y=58 cents - eq 2
Now multiply eq 1 with 5 and ex 2 with 2 this gives us : 10x+15y=285
10x+2y=116 Noe subtract eq 2 frm 1 this gives us :
13y=169
y=13 Now put the value of y in eq 1 and you can find the value of X...Problem solved!!!!
Cost of 2 pens and 3 rulers: 2x+3y=57
Cost of 5 pens and 1 ruler: 5x+y=58 ( Now solve this simultaneous equation)
Multiply 2 eq with 3: 3(5x+y)=58*3
This give us: 15x+3y=174
Now: 2x+3y=57
15x+3y=174 (Change the sign)
- - - ( Cut +3y with -3y)
This give us: -13x=-117
x=9
Put the value of x in eq 1:-
2(9)+3y=57
18+3y=57
3y=57-18
3y=39
y=13
PROBLEM SOLVED..
Cost of 5 pens and 1 ruler: 5x+y=58 ( Now solve this simultaneous equation)
Multiply 2 eq with 3: 3(5x+y)=58*3
This give us: 15x+3y=174
Now: 2x+3y=57
15x+3y=174 (Change the sign)
- - - ( Cut +3y with -3y)
This give us: -13x=-117
x=9
Put the value of x in eq 1:-
2(9)+3y=57
18+3y=57
3y=57-18
3y=39
y=13
PROBLEM SOLVED..