Question 610133
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Hi, Re:Your TY
(1, -2) 4x-3Y=10 or 4*1+3*2=10 4+6=10  Yes
x+4y=7 or 1+4*(-2)=7   1+(-8)=7  No:  -7 &#8800; 7
Might Check Your Sign in EQ II: {{{x +4y = -7}}} would yield the solution (1,-2) {{{-19y = 38}}}, y = -2 and x = 1
I.  4x-3y = 10
II. x+4y = 7              ||Signs SO important to the Solution
   4x-3y = 10
  -4x-16y = -28
     -19y = -18
        y = 18/19 = 0.947368421052632  and  x = 3.21052631578947
(1,-2) is a Pt on the fist line, not the 2nd line. The Solution for this system
of Two EQ, is as You found: x = 3.21052631578947, y = 0.947368421052632 

{{{drawing(300,300,   -6, 6, -6, 6,   grid(1),
circle(1, -2,0.2),
circle(3.2105263, .9474,0.2),
graph( 300, 300, -6, 6, -6, 6,0,(4/3)x-10/3, -.25x + 7/4))}}}