I don't understand how to solve this
9x^2 – 16 = 0

You will be solving for X. x =4/9

Step-by-step explanation:

You start by adding 16 to both sides.

then you have 9x^2 = 16

take the square root of each side

so you are left with 9x=4

then you divide each side by 9 to find the value of x

in this case, x=4/9

(3x-4)(3x+4)

Step-by-step explanation:

a^ 2 − b^ 2 = ( a + b ) ( a − b )

9 x 2 − 16 = ( 3 x )^ 2 − ( 4 )^2  

( 3 x )^2 − ( 4 )^2  = ( 3 x − 4 ) ( 3 x + 4 )

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.