I have got given homework 2 do with lots of these equations can u help me with a few so that i can get started.
x+7>12
5(2x-1)>5
3x+11 >35
Thanks
2006-10-24 13:59:39 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x+7-7 > 12-7
x>12-7
5(2x-1)/5 > 5/5
2x-1+1>5/5+1
2x/2>(1+1)/2
x>2/2
3x+11-11 > 35-11
3x>35-11
3x/3>(35-11)/3
x>(35-11)/3
Denada
2006-10-24 14:08:38 · answer #1 · answered by McCue-Tuk,Biologist 2 · 0⤊ 0⤋
What you have posted are inequalities, not equations. Solve them in the same way you solve equations, by doing the same operation (add, subtract, multiply or divide) to both sides. However, when solving inequalities, if you multiply or divide by a negative number, the sense of the inequality changes. For example
4 > 3
If I multiply both sides by -2
-8 > - 6
is no longer true, but
- 8 < - 6
is true.
x + 7 > 12
x > 5 {subtract 5}
5(2x - 1) > 5
2x - 1 > 1 {divide by 5}
2x > 2 {add 1}
x > 1 {divide by 2}
3x + 11 > 35
3x > 24 {subtract 11}
x > 8 {divide by 3}
Example of the aforementioned exception
5 - x > 3
- x > - 2 {subtract 5}
x < 2 {multiply by -1}
If you look at the original inequality, you see that it is true only when x is less than 2
2006-10-24 21:12:35 · answer #2 · answered by kindricko 7 · 0⤊ 0⤋
To get the answer to your 3 problems here is how to solve each one
x+7>12 x+7-7>12-7 x>5
5(2x+1)>5 10x+5>5 10x+5-5>5-5 10x>0 10x/10>0/10 x>0
3x+11>35 3x+11-11>35-11 3x>24 3x/3>24/3 x>8
2006-10-24 21:09:24 · answer #3 · answered by berths6 1 · 0⤊ 0⤋
these are called inequalities because of the inequality symbol.
x + 7 > 12
-7 -7
x > 5
5(2x - 1) >5
10x -5 >5
+5 +5
10x > 10
divide each side by 10
x > 1
3x + 11 > 35
-11 -11
3x > 24
divide both sides by 3
x > 8
to solve equations and inequlaities....your goal is to isolate the variable
2006-10-24 21:04:42 · answer #4 · answered by dla68 4 · 0⤊ 0⤋
If you understand equations like 3x+11=35 then you can solve this. the answer to the last one would be x >8 meaning, this equation is true with any value of x that is greater that eight. Does that answer your question
2006-10-24 21:06:14 · answer #5 · answered by amberacs 1 · 0⤊ 0⤋
x+7>12 ... subtract 7 from both sides, therefore, x>5
5(2x-1)>5 ... divide both sides by 5, so 2x-1>1... then, add 1 to both sides, so 2x>2... then divide both sides by 2, so x>1
3x+11>35 ... subtract 11 from both sides, so 3x>24 ... then, divide both sides by 3, so x>8
2006-10-24 21:03:57 · answer #6 · answered by Sara K 1 · 0⤊ 0⤋
They're inequalities not equations
But you treat them like equations:
x +7 > 12 (minus 7 from each side)
x>5
2006-10-24 21:04:43 · answer #7 · answered by Benny B 2 · 0⤊ 0⤋
Hi. If you meant to use the ' > ' sign, which means 'greater than', in your first problem x (which would equal 5 if the sign was ' = ' ) has to be any number more than 5.
2006-10-24 21:04:20 · answer #8 · answered by Cirric 7 · 0⤊ 0⤋
? #1 what is the opposit addition
? #2 do the work in the brackets first(2x1=?)
? #3 timesx =+11
sorry I won`t do the work
2006-10-24 21:08:26 · answer #9 · answered by gussie r 3 · 0⤊ 0⤋
x + 7 > 12
x>5
5(2X-1)>5
10X-5>5
10X>10
x>1
3x+11>35
3x>24
x>8
You're Welcome
2006-10-24 21:06:52 · answer #10 · answered by Goose 2 · 0⤊ 0⤋