Thread: Compass test

I'm trying to get into college. I'm really bad at math. Never even quite learned fractions,highschool drop out, and sleep in every highschool class. I don't know where in math I would really start. I really want to do good in this test, and have one week to study. They're going to have questions like this.

• Evaluate 2x³ – x² – 4in+ 2 at x = –3

• I need to plug in "–3" for the "x", remembering to be careful with my parentheses and thenegatives:
  
  
  • 2(–3)³ – (–3)² – 4(–3) + 2
    = 2(–27) – (9) + 12 + 2
    = –54 – 9 + 14
    = –63 + 14
    = –49

I figured out everything except how 4(–3) + 2 gets turned into a positive. Sorry I copied and pasted and can't turn the bold off lol

note ...

2(-3)³ - (-3)² - 4(-3) + 2

-4 times -3 is +12 , add 2 to get 14

oh thank you. I've been stuck on that.... Is there any easier way to add the (-3)3? because adding number when they get up there is just to crazy. there's no way on a test. Like if it's (12) powered by 14 or something. and I doubt they'll let me use a scientific calculator on the test.

Originally Posted by dropkicksidekick

.... Is there any easier way to add the (-3)3? because adding number when they get up there is just to crazy. there's no way on a test. Like if it's (12) powered by 14 or something. and I doubt they'll let me use a scientific calculator on the test.

if you mean (-3)³ , you are expected to know ...

(1) that a negative number cubed is a negative, and

(2) that 3 cubed is 27

I really don't believe you need to worry about evaluating 12¹⁴

in elementary when they taught times tables, did they do the same concept with powered numbers in highschool?

so you automatically know what something cubed something is. and regular tests can you use scientific calculators?

Look up the rules for the test you're taking ... I can't say much about it since I'm not familiar with the test you're taking.