@Ajai_Raj,
Here’s how to approach that second one:
You’re correct that the lines intersect but not for the reasons you give.
If you ended up with the equation being 4 = 4 then that would mean the lines are identical, but that shouldn’t have been the answer you ended up with.
Here are the 2 equations after rearranging and simplifying;
- y = 2x + 4
- y = -2x + 4
So they’re definitely not identical and the different signs in front of the ‘x’ mean they have opposite gradients.
Once you’re comfortable reading equations like these, you could probably look at them and also say that they intersect at (0,4) but if you wanted to work it out properly you could use one of the simultaneous solving methods.
Here’s the answer using substitution:
- y = 2x + 4
- 2x + y = 4
Substitute equation 1 into 2.
2x + (2x + 4) = 4
2x + 2x = 4 - 4
4x = 0
x = 0
Then solve for y;
(2*0) + y = 4
y = 4
I hope that helps.