Question

Penyelesaian dari sistem persamaan 2x-5y =18 dan 5x-3y =26 adalah x dan y. nilai 4x-7 adalah
Dgn Cara...

Answer 1

2x-5y=18 => x dikalikan 5
5x-3y=26 => x dikalikan 2
_____________________
10x-25y=90
10x-6y= 52
_________________________-
-19y= 38
y= 38/-19
y= -2
nilai x
2x-5y = 18
2x - 5.(-2) = 18
2x- (-10) = 18
2x + 10 = 18
2x = 18-10
2x= 8
x = 4
jadi nilai dari 4x-7 = 4.(4) - 7 = 16-7 = 9

Answer 2

Diselesaikan dengan cara subsitusi dan eliminasi cara penyelesaian
2x-5y=18 | x 3 | 6x-15y = 54
5x-3y=26 | x 5 | 25x-15y = 130 -
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-19x = -76
x = -76/-19
= 4
2x-5y = 18 --> 2(4)-5y = 18
8-5y = 18
-5y = 18-8
-5y = 10
y = 10/-5
= -2
nilai 4x-7 = 4(4)-7 = 16-7 = 9
kalo soalnya 4x-7y = 4(4)-7(-2) = 16+14 = 30