By the Pythagoras theorem, in a right triangle with the sides being a and b,
a² + b² = Hypotenuse²
Hypotenuse² = 4² + 4²
Hypotenuse² = 16 + 16 = 2*16
Hypotenuse = √2 * √16
Thus, hypotenuse = 4√2
Answer:
x > 30
Step-by-step explanation:
divide both sides by 9
this gets the x on one side by itself.
270/9 = 30
don't let the inequality mess with you
treat it like an equal sign and leave it the way it is.
move things around it.
So, let's make these two values improper fractions so they're easier to work with. 
So, to get the rate he grew in those months we have:
And to get the rate he grew in one month we have to divide both our numerator and our denominator by 21 to get:
aka he grew 1.24 inches in a month.