Question

Which equation is an identity

Answer 1

A 11-(2v+3)=-2v-8

B 5w+8-w=6w -2(w-4)

C 7m-2 =8m+4-m

D 8y + 9 =8y-3

Answer 2

b

Answer 3

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

Answer 4

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.
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.