This recipe makes 12 portions of potato soup. Richard follows the recipe but wants to make 4 portions.
Complete the amounts of each ingredient that he needs.

Recipe: Serves 12
72 mL oil
180 g onions
1.2 kg potatoes
1.32 L milk ​

three-fourths of an hour

36÷48=0.75

0.75=

ok thats very interesting

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81

y = -1

x = 8

hope this !