Question

Help me plz!!!!! I have no ideia how to do this

Answer 1

Answer:

x² = -3

Step-by-step explanation:

In algebra, the goal is always to isolate the variable, so its value can be determined.

Step 1: Subtract 21

7x² = -21

Step 2: Divide by 7

x² = -3

Step 3: Check

7(-3) + 21 = 0

0 = 0 ✔

Step 4: Answer

x² = -3

I'm always happy to help :)