Also, How do I factorise these?

x²-49

x²-9

x²-16

Step-by-step explanation:

x2 - 49

Both are squares so

Square root (x2) - Square root (49)

= x - 7

The other two answers are x - 3 and x - 4

Use the formula (x-a)(x+a)=x^2 - a^2

so what is the square root of 49, 9, and 16? By finding the square root you get a, and you can just plug it into the formula. For example the first one, 7 is the square root of 49. So, (x-7)(x+7)

seems like d

step-by-step explanation:

the answer is c)8

step-by-step explanaction: