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39 votes
39 votes
3.

Which equation is an identity?


A. –3y + 3 = –3y – 6

B. 9 – (2v + 3) = –2v – 6

C. 3w + 8 – w = 4w – 2(w – 4)

D. 7m – 5 = 8m + 7 – m

User Donkopotamus
by
2.9k points

2 Answers

12 votes
12 votes

Answer: C. 3w + 8 – w = 4w – 2(w – 4)

Identity equations are equations that are true no matter what value is plugged in for the variable. If you simplify an identity equation, you'll ALWAYS get a true statement. Learn about identity equations in this tutorial, and then create your own identity equation.

Step-by-step explanation: Algebra.com

a. 11 - (2v + 3) = -2v - 8

Simplify

11 - 2v - 6 = -2v - 8

5 - 2v = -2v - 8

Add 3v to both sides

5 = -8

That's false, so it is not an identity.

b. 5w + 8 - w = 6w - 2(w - 4)

Simplify

4w + 8 = 6w - 2w + 8

4w + 8 = 4w + 8

That's exactly the same on both sides, so it's

an identity.

c. 7m - 2 = 8m + 4 - m

7m - 2 = 7m + 4

Subtract 7m from both sides:

-2 = 4

That's false, so it is not an identity.

d. 8y + 9 = 8y - 3

Subtract 8y from both sides:

9 = -3

That's false, so it is not an identity.

3. Which equation is an identity? A. –3y + 3 = –3y – 6 B. 9 – (2v + 3) = –2v – 6 C-example-1
3. Which equation is an identity? A. –3y + 3 = –3y – 6 B. 9 – (2v + 3) = –2v – 6 C-example-2
User Axvo
by
3.2k points
16 votes
16 votes

Answer:

i think B but I’m not 100% sure lol

Explanation:

Here’s what I found on this app

3w + 8 - w = 4w - 2(w - 4)

2w + 8 = 4w - 2w + 8

2w + 8 = 2w + 8

0 = 0

User Ollie Strevel
by
2.6k points