How to solve this sum using this identity

(x+a) (x+b) = x sqaure+(a+b)x +ab

que is (x-9) (x+7) . negative and postive signs are con fusing

WHAT ARE THE FORMULAS FOR FINDING THE INITAL SPEED

What is the formula of \[{x^2} + {y^2} + {z^2}?\

What is a dodging number?

What is the value of $ 5 $ million dollars in Indian rupees given that one dollar is equal to $ 75 $ Indian rupees.

How many perfect cubes can you find from 1 to 100? How many from -100 to 100?