Solving inequalities Part 2?

Question

How do you do these problems:
1. -9<4x +3<11
2. 14 >3x-1>-10
3. 2(x-1)<-4 or 2(x-1)>4

Sove each problem by writing an inequaliy.
A salesperson earns $ 350 per week plus 10% of her weekly sales. Find the sales necessary for the salesperson to earn atleast $800 in one week

Xul is two years older than his sister Maria. The sum of their ages is greater than 32. Describe Maria's age.

Solve each problem by writing a compound inequality.
Watermelons cost $.39 per pound at a local market. Kent's watermelon cost between $4.00 and $5.00 what are the possible weights of his watermelon?

A concrete slab requires between 10 and 12 yd3 of concrete. If 2.5 yd3 of concrete can be poured each hour, how long will it take to pour the slab?

Answer 1

1) -9<4x+3<11
-3 -3 -3
-12<4x<8
/4 /4 /4
-3
2) 14 >3x-1>-10
+1 +1 +1
15>3x>9
/3 /3 /3
5>x>3 is your answer

3) 2(x-1)<-4 or 2(x-1)>4
2x-2<-4 or 2x-2>4
+2 +2 +2 +2
2x<-2 or 2x>6
/2 /2 /2 /2
x<-1 or x>3 is your answer

4) here's the inequality, use Q&As above to solve by yourself
350+0.1x >(or equal to) 800

5) here's the inequality, use Q&As above to solve by yourself
x+(x+2)>32

6) here's the inequality, use Q&As above to solve by yourself
4<0.39x<5

7) here's the inequality, use Q&As above to solve by yourself
where x equals an hour 10<2.5x<12

if your having trouble finding the answers to the last questions, post another question and i will be glad to give you the answers, but try them yourself first

could you please vote this as a best answer

Answer 2

your lucky I like doing these...
1.
-9<4x+3<11
-9<4x-8<0
-1<4x<0
-.25
2.
14>3x-1>-10
14>3x+9>0
5>3x>0
1.666(r)>x>0

3.
2(x-1)<-4
2x-2<-4
2x<-2
x<-1

thats it get somone else to do the rest...oh and I may not be right :P

Answer 3

I would not trust Mark D to answer any of my questions as he does not know how to do these problems correctly