Go to m-a-t-h-w-a-y they give you the answer. But only do it when absolutely necessary. Hope this helps!
The answer for the first one is 4 the sacend one is 49/2 the thirst one is 33223
I think 7x-y=-2 is the answer
Differentiate:
-5×2(xe^x^2)y-5e^x^2dy/dx=1
-5e^x^2(2xy+y´)=1
When x=-5, y=0:
-5e²⁵y´=1, so y´(-5)=-eˉ²⁵/5
