A) 3= x + 7
b) -7a-49

b im pretty sure hope this helps :)

Step-by-step explanation:

A: x = -4

B: a = -7 (I'm assuming the '-' in front of 49 was supposed to be an '=')

Step-by-step explanation:

A: You need to group the like terms together, and isolate the variable, which in this case is x.

Take the 7 over to the other side, so the equation looks a little bit like this.

3-7 = x.

3-7 is -4, so we've gotten our answer.

x = -4.

B: -7a = 49.

When two negative numbers are multiplied together, the product becomes positive.

49 is 7x7.

-7 times -7 would be 49.

So, in this situation, a would be -7.

a = -7.

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong