Hi, my name is Ashley. I'm in 7th grade (Pre-algebra) Student question.
I've got 2 questions. We (my dad and I) can not figure them out. please help me.
- 21 = 9 - 2 (4a + 2) and I am supposed to find out what the variable is.
- 2/3 n + 3/8 n = 15/16 (those are fractions). Again, I need to find out what the variable is.
Thank you very much for your help.
- I would first work with the right side of the equation. Multiply -2 by 4a + 2 to get
21 = 9 - 2 (4a + 2)
21 = 9 -8a - 4
Since 9 - 4 is 5 so this becomes
21 = 5 - 8a
Now, using the "balance" analogy for an equation, you can subtract 5 from both sides and maintain the balance. Thus
21 - 5 = 5 - 8a - 5
16 = - 8a
Now can you find a?
Two-thirds of n plus three-eights of n is two-thirds plus three eights of n. That is
2/3 n + 3/8 n = 15/16
(2/3 + 3/8) n = 15/16
Add 2/3 and 3/8 by first finding a common denominator, and then see if you can find n.
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