Respuesta :
Answer:
^2 on a number means you times the number by itself. You would change 9x^2 to 81x
Step-by-step explanation:
Answer:
x = √11
Step-by-step explanation:
9x² - 12 = 87
=> 9x² = 87 + 12
=> 9x² = 99
=> x² = 99/9
=> x² = 11
=> x = √11
=> x = 3.3 [approximately]