Question

Really need help! Been trying to solve for a while.

1. Solve the system by using a table. 3y=4x+7 , -4x-4y=28. These are the possible solutions:(–4, –3),(–3, –4), (4, 3),(3, 4).

2.Solve by graphing. -3x-y=-10, 4x-4y=8. possible solutions:(-1,3), (3-1), (1,3), (3,1)

Answer 1

3y=4x+7 ; 4x - 3y = -7 .... equn 1
-4x - 4y = 28
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-7y = 21 ; y = 21/-7 = -3
Substituting value of y in equn 1
4x - 3(-3) = -7
4x +9 = -7
4x = -7 -9
4x = -16
x = -4
Solution : (-4, -3)
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-3x - y = -10 .... equn 1
4x - 4y = 8 .... equn 2
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x - 5y = -2 ; x = 5y - 2
Substituting value of x in equn 1
-3(5y - 2) -y = -10
-15y + 6 -y = -10
-16y = -10 - 6
-16y = -16
y = 1
Substituting value of y in equn 1
-3x - 1 = -10
-3x = -9
x = 3
Solution : (3,1)