First divide by 4 to get x^2=9. Then take the square root of both sides. x=3 and x = -3.
Because a triangle's angles need to equal 180, you can subtract 100(30+70) and you will get 80. So 80 will be your third angle.
Answer:
In the area that she observed, the water level fell 13.64mm over 6.4 years, for an average annual rate of change of: -13.64 ÷ 6.2 = -2.2 mm/ year.
The correct answer will be 5z^3
