Question

I had an Algebra question that I did, but my answer isn't in the answer choices, can someone explain to me what I might have done wrong?

This is the question: Solve the open sentence.
8 < 2b OR 2b + 15 < 5

And these are the answer choices:
b < –2 OR b > 3
b > –3 OR b < 4
b > 4 OR b < –5
b > –1 OR b < 3

Answer 1

This is what I did on the left inequality:
8 < 2b
8/2> 2b/2
4>b
b<4

And this is what I did on the right inequality:
2b + 15 < 5
2b + 15 - 15 < 5 - 15
2b/2 > -10/2
b > -5

Answer 2

@ganeshie8 Do you think you can help me with this Algebra problem?

Answer 3

thats a very good try!

Answer 4

Thanks! The thing is, my answer isn't one of the answer choices. Do you think I did something wrong?

Answer 5

only mistake i see in your work is that you're flipping the inequality even when you're not multiplying/dividing by a negative number

Answer 6

you should flip inequality ONLY when you multiply/divide a negative number both sides

Answer 7

OH!! Your right! I always forget that you only flip it for negative numbers!

Answer 8

8 < 2b

suppose "b" is your height
we're saying that 8 is less than 2 times your height

Answer 9

lets solve it

8 < 2b

divide 2 both sides

4 < b

so 4 is certainly less than your height, right ?

Answer 10

which is same as saying :

your height is GREATER than 4

Answer 11

so b > 4 is the solution to that inequality

Answer 12

Right

Answer 13

And for the other inequality the answer would be: b < -5

Answer 14

You got it !

Answer 15

Yay! Thank you so much! I think now I have to graph it.