Factorise: X squared - 16

x² - 16

= x² - 4²

= (x+4)(x- 4)

Step-by-step explanation:

You know it has to be x squared so in the first part of your brackets it would be an x (x    )(x    ). Then you have to find out what times what is 16... in this case it is 4... (x    4)(x    4). Next you have to know the rules regarding negatives and positive... if you know that, you should be able to work out that it would be (x-4)(x+4)... you can check this using the foil method (x times x, x times 4, -4 times x and -4 times 4) or smiley face method... hope this helpedFactorised means put into brackets...

94

step-by-step explanation:

average the numbers and use a variable to figure out the minimum to get a 90.

(79+94+91+92+x)/5=90

x = 94