Q. 5 pencils and 7 pens together cost Rs.50. 7 pencils and 5 pens together cost Rs.46. Find the cost of 3 pencils and 1 pen. Also find the area of triangle found by two lines and x - axis. Write coordinates of vertices of triangle.
Answers
Answered by
1
let cost of one pencil be rsX and cost of one pen be RS y
5x+7y=50 equation 1
7x+5y=46 equation 2
multiplying equation 1 by 5 and equation 2 by 7
we get
25x+35y=250
49x+35y=322 simultaneous equation
(-) (-) =(-)
-24x=-72 (-) sign will be eliminated when divided x=3
when u will put the value x in equation 1 u will get 15+7y=50... y=5
cost of 3 pencils 3*3=9 and cost of one pen =5
total cost 9+5=14.. RS14 ur answer.. any problems write in comment box
5x+7y=50 equation 1
7x+5y=46 equation 2
multiplying equation 1 by 5 and equation 2 by 7
we get
25x+35y=250
49x+35y=322 simultaneous equation
(-) (-) =(-)
-24x=-72 (-) sign will be eliminated when divided x=3
when u will put the value x in equation 1 u will get 15+7y=50... y=5
cost of 3 pencils 3*3=9 and cost of one pen =5
total cost 9+5=14.. RS14 ur answer.. any problems write in comment box
Similar questions