Question 149776
Solve the system of equations. 
1.5x – 7y = 2
0.625x + 3y = –2.125
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get rid of fractions for convenience
3x - 14y = 4  (x2)
5x + 24y = -17 (x8)
I'll use determinants
x  y   1
3  -14 -4
5  24  17
Det = 3*24 - 5*(-14)
Det = 142
142x = -14*17 - 24*(-14)
= -238 + 96
= -142
x = -1
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-142y = 3*17 - 5*(-4)
= 51 + 20
=71
y = -71/142
y = -1/2