Question

4y+5x=15

Answer 1

$If...x=8y+3$ ⇒ $4y+5x=4y+5\cdot(8y+3)=4y+40y+15=44y+15$

$44y+15=15$ ⇒ $44y=0$ ⇒ $\boxed {y=0}$

$x=8\cdot0+3$ $\boxed { x=3 }$

Answer 2

4y+5x=15x=8y+3

4y+5*(8y+3)=15

4y+40y+15=15

44y=0

y=0

x=8y+3

x=8*0+3

x=3