smile asked in Science & MathematicsMathematics · 8 years ago

# math help!! solving with elimination-Non standard form !?

4x + 7y = 47

5x - 4y = -5

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• 8 years ago

4x + 7y = 47 ...........(1)

5x - 4y = -5 .............(2)

(1) *5 gives 20x +35 y = 235.......(3)

(2)*4 gives 20x -16y = -20........(4)

(3) - (4) gives 51 y = 255

y = 255/51 =5

substitute the value of y in (1) gives 4x +7*5 =47

4x +35 = 47

4x = 47-35 =12

x = 12/4 = 3

check;( 4*3) +(7*5) =12+35=47

• Joe
Lv 5
8 years ago

4x + 7y = 47

5x - 4y = -5

14x +28y = 188

35x - 28y = -35

49x = 153

x = 153/49

35(153/49) - 28y = -35

765/7 - 28y = -35

765 - 196y = -245

- 196y = -1010

y = 505/98

(306/98,505/98)

• 4 years ago

9x-3y=sixty 3 7x-3y=40 5 9x-3y=sixty 3 -7x=3y=-40 5 (-3y and +3y gets canceled and the rest we resolve it) it turns into:- 2x= 18 then, x=18/2=9 therfore, x=9 to locate y(exchange the cost of x in anybody eq.) 7x-3y=40 5 7(9)-3y=40 5 sixty 3-3y=40 5 -3y=-18 y=6 for this reason the cost of: x=9 , y=6