Write the slope-intercept form of the equation of the line that passes through the point (-5,4) and has a slope of -1.
y = mx+b
4 = -1(-5)+b
4 = 5+b
9 = b
y = 5x+9
I don't see what I missed. Do I subtract 5 on both sides? that would be y = 5x-1
y = mx+b
4 = -1(-5)+b
4 = 5+b
OK to here
9 = b No
y = 5x+9 No
I don't see what I missed. Do I subtract 5 on both sides? Yes
that would be y = 5x-1
No, the gradient is -1.
So go back to the original
y=mx+b
m=-1 and b=-1 and substitute
y=-1x-1
Check by substituting the values if x=-5
y=-1(-5)-1 = 4