I need some help with this question

(7w + 9x)(7w - 9x)

Step-by-step explanation:

 Given expression;

        49w²  - 81x²

Now to solve the problem;

         49w² - 81x² = 7²w² - 9²x²

Using differences of two squares;

        x²  - y²   = (x + y)(x - y)

So;

7²w² - 9²x²  = (7w + 9x)(7w - 9x)

whatever you can spend with $11.53 or under.

step-by-step explanation:

20 - 8.47 = 11.53. take away the money he used for lunch from the starting amount of 20.

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,