Question

Jordan solved the equation −7x + 25 = 48; his work is shown below. Identify the error and where it was made. −7x + 25 = 48 Step 1: −7x + 25 − 25 = 48 − 25 Step 2: −7x = 23 Step 3: negative seven times x over seven = twenty-three over seven Step 4: x = twenty-three over seven Step 1: He should have added 25 to each side. Step 1: He should have divided both sides by −7. Step 3: He should have divided both sides by −7. Step 3: He should have multiplied both sides by −7.

Answer 1

The error is in Step 3. Jordan should have divided both sides by -7, not 7. Instead of x = 23/7, the answer is x = -23/7.

Answer 2

Step 3, he should have divided both sides by -7 instead of positive 7 otherwise they won't cancel out.

Hope that helps.