Question 34863
x-7=y  and 2y+25=3x  
Re-Arranging
X-Y=7
3X-2Y = 25
*[invoke linear "x", "y", 1, -1, 7, 3, -2, 25 ]

*[invoke linear_substitution "x", "y",1, -1, 7, 3, -2, 25 ]