Respuesta :

Answer:

a = -9

Step-by-step explanation:

a+(-4)=-13

add 4 to each side

a-4+4 = -13+4

a = -9

Answer:

a = - 9

Step-by-step explanation:

a  + (-4) = -13

Add  4 to both sides

a + (-4) + 4 = -13 + 4

       a + 0 = -9

        a = -9

When two numbers have different sign, subtract and the result will have the sign of the bigger number