i dont know how to do this and considering i don't have a graph on the paper i'm using, i need help on how to solve this without a graph or having to plot anything :( plz help!! even if you just give me the formula or steps to do this, i will be much appreciative!

i dont know how to do this and considering i dont have a graph on the paper im using i need help on how to solve this without a graph or having to plot anything class=