substitution/elimination
- Thread starter humakhan
- Start date
yeah i checked and its wrong
because if you put the x and y into their place... one equation doesn't come out right...
like
3 (2) + 2 (-9) = - 12
6 + (-18) = -12
which is correct
but.
2 (2) + (-9) = -7
4 + (-9) = - 5 not -7
wrong
so instead of substitution you have to use elimination...let me try it.
because if you put the x and y into their place... one equation doesn't come out right...
like
3 (2) + 2 (-9) = - 12
6 + (-18) = -12
which is correct
but.
2 (2) + (-9) = -7
4 + (-9) = - 5 not -7
wrong
so instead of substitution you have to use elimination...let me try it.
You don't "have to" use either method. They both work on any problem of this type and both give the same answer. You should know both methods and pick the one that works best for a particular problem. Substitution looks good to me, once you have correctly solved for y in 2x+y=-7.