This would be easiest to do by completing the square.
x^2+10x-2=0
x^2+10x=2
x^2+10x+25=27
(x+5)^2=27
x+5=±√27
x=-5±√27
(x+5+√27)(x+5-√27)
Multiply 10 and 3 then subtract five from 10 add the product and the difference add that sum to 10
Answer:
The Chef will prepare 320 soups for a large banquet
Step-by-step explanation:
chef thinks that 2 out of every 5 dinner guests will order soup
===> Order soup / total number of attender
= 2/5
Total guest = 800 ==> 4 people ordered soup is
2 /5 = x /800
cross multiplying
x = 2 x 800 / 5
= 320
The Chef will prepare 320 soups for a large banquet