Solve:

3x + 7y + 5= 0
4x - 3y - 8 = 0

Find p; if:
px + y - 1= 0

2 answers

3x+7y=-5 (i)
4x-3y=8 (ii)

(i)x 4:
12x+28y=-20 (iii)

(ii)x 3:

12x-9y=24 (iv)

(iv)-(iii):
-37y=44
y=-44/37

subs y into (i):
3x+7(-44/37)=-5
3x= -5+308/37
x=148/37
3x = -185/37 + 308/37 = 123/37
x = 41/37