if a + b + c = 9 and a square + b square + c square = 35 the find the value of ab + bc + ca .​ I am in need of help

a+b+c=9 and a2+b2+c2=35 then by using identity

(a+b+c)2=a2+b2+c2+2ab+2bc+2ca,we get the answer 9x9=35+2(ab+bc+ca)

2(ab+bc+ca)=9x9-35

2(ab+bc+ca) =81-35then we get ab+bc+ca=46/2 so ab+bc+ca=23

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40