OpenStudy (tennisthegreat123):

Mia is three years older than twice the size of her sistser Brooke's age. The sum of their age is less than 30. What is the greatest age Brooke can be? A. 7 B. 8 c. 10 d. 9

2 years ago
OpenStudy (kiwibyrd):

we need to set up an inequality for this !

2 years ago
OpenStudy (kiwibyrd):

three years older : +3 twice the age : times 2

2 years ago
OpenStudy (kiwibyrd):

so mia's age = brooke's age times 2, plus 3

2 years ago
OpenStudy (kiwibyrd):

and then it has to be less than 30, so your equation would look like this$302b+3$

2 years ago
OpenStudy (kiwibyrd):

ah it messed up, i meant $30\ge 2b+3$

2 years ago
OpenStudy (tennisthegreat123):

Okay! So, we then would divide 2 by both sides?

2 years ago
OpenStudy (kiwibyrd):

yep, treat it like a regular equation and solve for b !

2 years ago
OpenStudy (tennisthegreat123):

So that would equal: 15 greater than or equal to b + 3?

2 years ago
OpenStudy (tennisthegreat123):

If you subtract 3 from both sides, it would equal 12. But 12 isnt an answer?

2 years ago
OpenStudy (kiwibyrd):

i honestly dont know ! in any case we know that the answer is 10 because it still checks out and is the highest answer

2 years ago
OpenStudy (tennisthegreat123):

Okay, thanks!

2 years ago
OpenStudy (kiwibyrd):

ah wait hold that thought

2 years ago
OpenStudy (tennisthegreat123):

oh

2 years ago
OpenStudy (kiwibyrd):

i was just checking, 10 is correct :]

2 years ago
OpenStudy (tennisthegreat123):

Okay! great

2 years ago