Highest common factor of 28,40,12 and 24​

Describe all the numbers that when rounded to the nearest thousand are 645,000

What is the effect on the graph of the parent function f(x) = x when f(x) is replaced with 3f(x)? a) shifts the line 3 units up b) shifts the line 3 units down c) increases the slope of the line by a factor of 3 d) decreases the slope of the line by a factor of 3

Which is the equation of a line perpendicular to the line with the equation 3x+4y=8