im stumbed some help please
7x=4y=-2
10x-3y=32
i need to use subsitution for this i dont get it? explain?
You have a typo in your first equation.
Not a real good candidate for substitution, but if you have to.....
Step 1: Solve the first equation for x or y (whichever is easier).
Step 2: Substitute that into your second equation to solve for your 1st variable.
Step 3: Finally, use your answer from Step 2 and substitute into Step 1 to solve for the 2nd variable.
After you fix your typo, I can be more specific.
Solve the first equation for x or y. Let's choose y for no reason.
$\displaystyle 7x+4y=-2$
$\displaystyle 4y=-7x-2$
$\displaystyle y=-\frac{7}{4}x-\frac{1}{2}$
Now substitute this back into the second equation.
$\displaystyle 10x-3\left(-\frac{7}{4}x-\frac{1}{2}\right)=32$
$\displaystyle 10x+\frac{21}{4}x+\frac{3}{2}=32$
$\displaystyle 40x+21x+6=128$
$\displaystyle 61x=122$
$\displaystyle x=\frac{122}{61}$
$\displaystyle x=2$
Now plug this value into either equation you started with to find y.