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Solving systems by substation
5x+2y=8
x+3y=-12

User AmerllicA
by
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2 Answers

0 votes

Answer:

x=48/13, y=-68/13

Explanation:

5x+2y=8

x+3y=-12 ==> solve for x

x = -12 - 3y ==> subtract 3y on both side to isolate x

5(-12 - 3y) + 2y = 8 ==> substitute -12 - 3y for x

5*(-12) - 5(3y) + 2y = 8 ==> distribute 5 to -12 and -3y

-60 - 15y + 2y = 8

-60 - 13y = 8 ==> solve for y

-13y = 68 ==> add 60 on both sides

13y = -68

y=-68/13 ==> divide 13 on both sides to isolate y

x + 3(-68/13) = -12 ==> substitute -68/13 for y

x + (-204/13) = -12 ==> solve for x

(x - 204/13 = -12)*13 multiply the equation by 13 to remove fractions

13x - 204 = -156

13x = 204 - 156 ==> add 204 on both sides to isolate x

13x = 48

x = 48/13 ==> divide 13 on both sides to isolate x

Answer: x=48/13, y=-68/13

User Beer
by
5.0k points
2 votes

Answer:

y = -68/13

x = 48/13

Explanation:

5x+2y=8

x+3y=-12

Time the second equation by -5

5x+2y=8

-5x - 15y = 60

-13y = 68

y = -68/13

Put -68/13 back in and solve for x

5x+2(-68/13) =8

5x + 8 = 8

5x = 0

x = 48/13

User Ryne Everett
by
4.9k points