Step-by-step explanation:
the line equation is in the slope-intercept form.
that looks like
y = ax + b
"a" is the slope (always the factor of x). "b" is the y-intercept (the y value when x = 0).
so, when it says "the same slope", we know we have to use the same factor of x.
and yes, the coordinates of a point are (x, y). so, you really need to use it in the places of x and y to get "b".
9.
y = -4x + b
2 = -4×0 + b = b
so, yes, the equation is
y = -4x + 2
but as you can see : b is NOT y in general.
10.
y = 2/3 x + b
-1 = 2/3 × 4 + b = 8/3 + b
now, let's multiply both sides by 3 to get rid of the fraction :
-3 = 8 + 3b
-11 = 3b
b = -11/3
so, the equation is
y = 2/3 x - 11/3
or
y = 1/3 × (2x - 11)
