I am gonna try my best to explain this to you :)
Firstly what you need to do is simplify the equation
[tex](x*2)+x(2^2)+(y*2^3)+(y*2^4)=42\\2x+4x+8y+16y=42\\6x+24y=42[/tex]
Now it looks a little less complicated the next step is to isolate y, in order to do that we solve the equation for y
[tex]6x+24y=42[/tex]
[tex]24y=42-6x\\y=\frac{42-6x}{24}[/tex] Simplify it [tex]\frac{7-x}{4}[/tex]
Now substitute y for [tex]\frac{7-x}{4}[/tex]
[tex]6x+\frac{7-x}{4}=42\\4(6x)+7-x=42*4\\24x+7-x=168\\23x+7=168\\23x=168-7\\23x=161\\x=\frac{161}{23}\\x=7[/tex]
Now substitute x for 7 and solve for y
[tex]6(7)+24y=42\\42+24y=42\\24y=42-42\\24y=0\\y=\frac{0}{42}\\y=0[/tex]
x=7 and y=0
Hope this helps :)
