Question 111177
I'll do one, you try the other one, and write back if you are still having trouble.
:
{{{4x+5y=6}}}
{{{(2/3)x-5y=7}}}
:
Using the first equation, solve for y:
:
{{{5y=6-4x}}}
{{{y=(6-4x)/5}}}
:
Now substitute this value for y into the second equation:
:
{{{(2/3)x-5((6-4x)/5)=7}}}
:
{{{(2x)/3-6+4x=7}}}
{{{(2x+12x)/3=7+6}}}
{{{14x=39}}}
{{{x=39/14}}}
:
Now substitute this value of x into the first equation:
:
{{{4(39/14)+5y=6}}}
{{{78/7+5y=6}}}
{{{5y=42/7-78/7}}}
{{{y=-36/35}}}
:
Check:
{{{(2/3)(39/14)-5(-36/35)=13/7+36/7=49/7=7}}}
{{{4(39/14)+5(-36/35)=78/7-36/7=42/7=6}}}, Check
:
Ok, the next one is yours.  Like I said, write back if you are still having trouble.  Just remember to be very careful with your signs and with the arithmetic in general.