Hello there! :)
The equation y=-3x+7 is written in slope-intercept form (y=mx+b)
Where
m is the slope
b is the y-intercept
As we can see, the slope of this line is -3.
Pay attention to the minus sign.
Hope it helps.
~An emotional teen who helps others with joy and listens to "How Far I'll Go"
-Grace ;-)
Good luck.