i have this test i have to submit today (we do it online) and i swear when we go to class we only talk about like 1 thing then on the quizzes and homework theres all this stuff that we’ve never gone over so im left with my thumb up my butt.

the shit that confuses me the most right now is trying to differentiate between a negative sign and a subtraction sign, i thought you were supposed to use captions to indicate a negative but this thing never does. i also dont understand what the reasoning behind changing a minus sign to an addition sign or vice versa is for example ill have something like idk,

7(5 - 6x) - 5(9 + 8x) = 15x - 9

i get you have to use distributive and get

35 - 42x - 45 + 40x = 15x - 9

but then the way they set it up im left unsure if the - signs are indicating they want me to add or subtract and then when i start to combine like terms the way i do it vs the way its supposed to be done will differ because of the addition or subtraction confusion because sometimes it changes.

so itd be like,

35 + -45 - 42x + 45x = 15x - 9

then im guessing its like

-10 - 87x = 15x - 9

+10 +10

-87x = 15x - 19

but it already looks fucked up from this point…er

so idk, im kinda lost over here any help to explain wtf im supoosed do with those type of problems would be appreciated.