Complementary angles add up to 90 degrees. Supplementary angles add up to 180 degrees, so no.
4x + 5y = 9
5y = -4x + 9
y = -4/5x + 9/5......slope intercept form (y = mx + b)
In y = mx + b form, which is what this equation is in now, the slope is in the m position and the y int is in the b position
y = mx + b
y = -4/5x + 9/5
so ur slope(m) = -4/5 and ur y int (b) = 9/5
30+4X=90 (right angle is 90°)
X=15
4 (15)= 60
30+60= 90 so you know it's right
