Given the system of equations:
[tex]\begin{gathered} 1.8x+3y=3\text{ } \\ -2x-2.5y=-5 \end{gathered}[/tex]Multiply the first equation by 2.5 and the second by 3 to eliminate y
So,
[tex]\begin{gathered} 4.5x+7.5=7.5 \\ -6x-7.5y=-15 \end{gathered}[/tex]Add the last equation :
[tex]-1.5x=-7.5[/tex]Divide both sides by -1.5
[tex]\begin{gathered} \frac{-1.5x}{-1.5}=\frac{-7.5}{-1.5} \\ \\ x=5 \end{gathered}[/tex]Substitute with x = 5 at the equation 1.8x+3y=3
[tex]\begin{gathered} 1.8\cdot5+3y=3 \\ 9+3y=3 \\ 3y=3-9 \\ 3y=-6 \\ y=-\frac{6}{3} \\ \\ y=-2 \end{gathered}[/tex]So, the solution of the system
[tex]\begin{gathered} x=5 \\ y=-2 \end{gathered}[/tex]
