That point slope equation given does not pass through those points, the point slope equation y + 7 = -0.4(x - 10) does, though. The standard form of that would be
2x + 5y = -15
You can get that by distributing the -0.4 out
y + 7 = -0.4x + 4
You can then add 0.4x to both sides, and subtract 7 from both sides to get
0.4x + y = -3
Now some teachers may accept this, but in correct standard form the coefficient of x is a whole number, so you have to multiply both sides by 5 to get rid of the decimal, and you get
2x + 5y = -15
