Factorising using difference of two squares :

a) (x + 1)² - 25
&
b) 49 - (1 - x)²

a) (x + 6)(x - 4)

Step-by-step explanation:

a) (x+1)^2 - 25

=(x+1)(x+1) - 5 x 5

Remember the formula for a difference of two squares is

a^2 – b^2 = (a + b)(a – b) or (a – b)(a + b)

so a = x+1 and b = 5

therefore to factorise it would be

(x + 1  + 5)(x + 1 - 5)

= (x + 6)(x - 4)

b) For the next one, it's a similar:

root 49 is 7, and the equation (1 - x) has been squared so

a = 7 and b = - (1 - x)

The last part is the same as a), if you still need help, just ask me :)

Tip: don't forget to incorporate the negative, it's important!

Hope this helped,

Cate

57 732

step-by-step explanation:

i dont really.know

answer: the 4 kilogram bag

step-by-step explanation: this is because if you divide the number of kilograms into the total it will tell you how much each individual kilogram would be worth. 2 kilos is 7 and change 3 would be around 6 ish and the 4 kilo would be 4.6 and change and the 5 kilos would be like 4.88