Question

B is between A and C. AB = 3x + 1, BC = 2x, and AC = 21. Find X.

Answer 1

`x = 4`

Explanation:

`AB + BC = AC \\ (3x +1) +(2x) = 21 \\ 3x +1 +2x = 21 \\ (3 +2)x +1 = 21 \\ 5x +1 = 21 \\ 5x +1 -1 = 21 -1 \\ 5x = 20 \\ (5x)/(5) = (20)/(5) \\ x = 4`

Answer 2

`\\ \ast\sf\hookrightarrow AB+BC=AC`

`\\ \ast\sf\hookrightarrow 3x+1+2x=21`

`\\ \ast\sf\hookrightarrow 5x+1=21`

`\\ \ast\sf\hookrightarrow 5x=21-1`

`\\ \ast\sf\hookrightarrow 5x=20`

`\\ \ast\sf\hookrightarrow x=(20)/(5)`

`\\ \ast\sf\hookrightarrow x=4`