Find the student’s error in solving the following inequality.
31 < –5x + 6
25 < –5x
–5 < x

Student's error is –5 < x.

Solution:

Step 1: Given inequality

31 < –5x + 6

Step 2: Subtract 6 from both sides of the inequality.

31 – 6 < –5x + 6 – 6

25 < –5x

Step 3: Multiply both sides by –1 to reverse the inequality.

25 × (–1) > –5x × (–1)

–25 > 5x

Step 4: Divide by 5 on both sides.

–5 > x

The correct answer is –5 > x.

Student's error is –5 < x.

step-by-step explanation:

use pothagarean therom

a^2+b^2=c^2 so first ac

acm is a right triangle because c= 90°

and am (the hypotenuse or c) =16+9 =25

but there is not enough info we need another angle or side length