I am having a hard time with simultaneous equations specifically the elimination method, i want to know when do we subtract and when do we add, so if u know how its done plz help im confused Example : 3x-2y =7
4x+y = 13

Listen!When we have + sign at the back we subdtract but when we have - sign at the back we add.For example:-

3x-2y=7

Here the question will be3x=2y+7

Then when we bring 7 back of 3x we will have to change the sign.

3x-2y=7

In this way we do we need to keep the opposite sign if multiplication the sign should be changed into division and if addition it should be changed into substraction and if substraction sign is there it should be changed into addition sign.

Step-by-step explanation:

Please add this to brainlist !

i think its a and d

step-by-step explanation: