Solve, using cross-multiplication
5x+4y+14=0
3x=−10−4y
xb1c2−b2c1=yc1a2−c2a1=1a1b2−a2b1 --A. That means, x=(b1c2−b2c1)(a1b2−a2b1)
y=(c1a2−c2a1)(a1b2−a2b1)
a1=5
b1=4
c1=14
a2=3
b2=4
c2=10
x=(b1c2−b1c1)/(a1b2−a2b₁)
y=(c1a2−c2a1)/(a1b2−a2b1)
x=40−5620−12
y=42−5020−12
∴x=−2
∴y=−1