The answer is y=-1/2x+4 that is if you are finding y. But if you are finding x it is x=-2y+8.
The formula for perimeter is 2L + 2W and the formula for the area is L * W, since we don't know the width we will divide 35:7 = 5 and he the measurement for the width.
Now just add L + W = 12 and multiply by 2 the answer is 24
Or 2 * 7 + 2 * 5 = 24
-5.5x+0.56= -1.64
-0.56 -0.56
-5.5x= -2.2
/5.5 /5.5
x= -0.4 is the answer
The requirement is that every element in the domain must be connected to one - and one only - element in the codomain.
A classic visualization consists of two sets, filled with dots. Each dot in the domain must be the start of an arrow, pointing to a dot in the codomain.
So, the two things can't can't happen is that you don't have any arrow starting from a point in the domain, i.e. the function is not defined for that element, or that multiple arrows start from the same points.
But as long as an arrow start from each element in the domain, you have a function. It may happen that two different arrow point to the same element in the codomain - that's ok, the relation is still a function, but it's not injective; or it can happen that some points in the codomain aren't pointed by any arrow - you still have a function, except it's not surjective.
At some point, the exponential function always exceeds a polynomial function.
