Step-by-step explanation:
the slope intercept form is
y = ax + b
"a" being the slope, "b" being the y- intercept (which is the y-value when x = 0).
the slope here :
in the table x is always increasing by 2.
and y is always investing by 1.
so, the slope is 1/2
the y-intercept :
we need to find the y-value for x = 0.
but we don't have a data point with x = 0 in the table.
so, we have to extend the structure of the table to the left.
x decreases by 2 (making it 0), and y decreases by 1 (making it -1).
therefore, the y- intercept (b) is -1.
and the line equation is
y = (1/2)x - 1
not sure about "the other method".
there is the point-slope form of the equation :
y - y1 = a(x - x1)
again with "a" begin the slope, and (x1, y1) being a point on the line.
if we get the y-intercept in the table, then this point is (0, y1).
and the equation would be
y - y1 = ax
in our case
y + 1 = (1/2)x
and another method ?
sometimes people write
nx + my = c
in our case starting with the original equation
y = (1/2)x - 1
2y = x - 2
-x + 2y = -2
x - 2y = 2
, we must do some algebra.
(at this point you should remember that dividing or multiplying an inequation by anegative number changes the direction of the inequality)..
. Then,we just have to add both sides 4, which yields
.
, which means that, if we divide both sides by 5, we obtain the value of y:
(in this case, the direction of inequality does not change because 5 is possitive).
