What are the common factors of 45,72,and 99

The factors of 45 are:   1, 3, 5, 9, 15, 45

The factors of 72 are:  1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72

The factors of 99 are:  1, 3, 9, 11, 33, 99

The common factors are: 1, 3, 9

Hope this helps. :)

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

(1,4) is on graph of f(x)

f(1) = 4

so 1/4 f(x)

1/4 f(1)

1/4. ×4

1

so point for function 1/4. f(x) is (1,1)