I don't understand what you mean by 'mentally' but anyways, here is how to solve it.
(z−12)(z+12)
=(z+−12)(z+12)
=(z)(z)+(z)(12)+(−12)(z)+(−12)(12)
=z^2+12z−12z−144
=z^2−144
Here,
Let the total number of students be x,
Then,
55% of x=550
x=1000
Answer:
9/16
Step-by-step explanation:
Next time write the mixed number like this:
1 1/3 just so you know so ppl can answer it better
Answer:
8
Step-by-step explanation:
The distributive property is when you have parenthesis like this ( ) and when a number is outside the parenthesis 5(2×3) like this you multiply the outside numbers by both inside numbers