Question

Daniel wrote the following two-column proof for the given information. Given: AB = 3x + 2; BC = 4x + 8; AC = 38 Prove: x = 4 Statements Reason 1. AB = 3x + 2; BC = 4x + 8; AC = 38 1. Given 2. AB + BC = AC 2. Angle Addition Postulate 3. 3x + 2 + 4x + 8 = 38 3. Substitution Property of Equality 4. 7x + 10 = 38 4. Combining Like Terms 5. 7x = 28 5. Subtraction Property of Equality 6. x = 4 6. Division Property of Equality On which line, did Daniel make his error? line 2 line 3 line 4 line 5

Answer 1

Line 2

Explanation:

Daniel wrote the following two-column proof for the given information.

Given: AB = 3x + 2; BC = 4x + 8; AC = 38

Prove: x = 4

Statements Reason

1. AB = 3x + 2; BC = 4x + 8;

AC = 38 1. Given

2. AB + BC = AC 2. Angle Addition Postulate

3. 3x + 2 + 4x + 8 = 38 3. Substitution Property of Equality

4. 7x + 10 = 38 4. Combining Like Terms

5. 7x = 28 5. Subtraction Property of Equality

6. x = 4 6. Division Property of Equality

On which line, did Daniel make his error?

line 2

line 3

line 4

line 5

Just did this one on odyssey

Answer 2

Given:
1. AB = 3x +2; BC = 4x + 8; AC = 38

2. AB + BC = AC incorrect (not an angle angle addition postulate)
3. 3x+2 + 4x + 8 = 38 correct
4. 7x + 10 = 38 correct
5. 7x = 28 correct
6. x = 4

Daniel made an error on line 2.