April 1, 2015

Homework Help: check math

Posted by Anonymous on Wednesday, August 8, 2007 at 4:39pm.

Here are my answers. Can you check if I got the right answers? Thank you!

(x+3)(x-3)>0 answer: x<-3 or x>3
x^2-2x-15</=0 answer: -3</=x</=5
12x^2=3x answer: x=1/4
sin2x=sinx, 0</=x</=2pi answer: x=pi
lx-3l<7 answer: (-oo,oo)
answer: x=-1,2,1/2
27^(2x)=9^(x-3)answer: x=-3/2
logx+log(x-3)=1 answer: x=-2, 5

(x+3)(x-3)>0 answer: x<-3 or x>3 ok
x^2-2x-15</=0 answer: -3</=x</=5 ok

12x^2=3x answer: x=1/4 also x = 0, (12x^2 - 3x = 0 ---> x(12x-3)=0 )

sin2x=sinx, 0</=x</=2pi answer: x=pi

no. recall that sin2x = 2(sinx)(cosx)
sinx(2cosx -1=0
sinx=0 or cosx=1/2
then x=0,pi,2pi from the first
or x = pi/3 (60) or 5pi/3 (300)

lx-3l<7 answer: (-oo,oo) No, -4≤x≤10

answer: x=-1,2,1/2 ok

27^(2x)=9^(x-3)answer: x=-3/2 ok

logx+log(x-3)=1 answer: x=-2,5
Your answer of x=-2 does not work in logx, you cannot take the log of a negative number. So just x=5

Answer this Question

First Name:
School Subject:

Related Questions

check math - Here are my answers. Can you check if I got the right answers? ...
8th Grade Algebra: Answer Check #2 - Add or Subtract (Radicals) { this means ...
Math - Hi, would someone mind just checking the answer I got for this formula ...
Math 8R: Homework Check - Part 2 - Part 2: Simplify by combining like terms and...
Algebra - Can someone check my algebra answers and help me with the problems I ...
Algebra - Would someone please check these answers? Simplify. 3/x-5+1/1-4/x-5 ...
maths - 1. Q: 2|3x-5| when x=(-3) A: 24 2. Q: |6-x|+4 when x=5 A: 5 ...
Calculus - please check my work - differentiate each function a) y = cos^3x b) y...
Pre-Calculus - Could someone check my answers? 25. 32^(2x-3)=2 Answer- x= 8/5 26...
8th Grade Algebra: Answer Check - Find the length of the 3rd side of each right ...