Verified Answer :

Equation:  y+7=-2/5(x-10)
y + 7 = -2/5 x + 4
y = -2/5 x - 3
2/5x + y = -3
Multiply the equation with 5, 
2x + 5y = -15

In short, Your Answer would be:  
2x + 5y = -15

Hope this helps!