Step-by-step explanation:
the slope (or gradient) of a line is the factor of x.
in our case here : 3
it is expressed as ratio y/x and represents the amount of units y changes (and via the sign in what direction), when x changes a certain amount of units (again, via the sign in what direction). like when going from a point 1 to a point 2.
so, here we have 3 = 3/1, and that means, when x changes by 1 unit to the right (positive), y changes 3 units up (positive).
the y-axis intercept is simply the point, where x = 0. clearly, any point with the x coordinate being unequal to 0 cannot be on the y axis.
so, here
y = 3×0 + 7 = 7
=>
the y-axis intercept point is (0, 7).
