Answer: number of adults = 3, number of children = 5
Step-by-step explanation:
let the number of adults be x, and the number of children be y.
x + y = 8 , 15x + 8y = 85
1st equation x 8 = 8x + 8y = 64

substitute x=3

Answer:
the third
Step-by-step explanation:
your photo is not clear, and your explanations for your question is not clear also.
as we are tackling the substraction and the addition questions between matricxs.We could simply +/- every number correspondingly.
Take 1/2 of b and squaer it so
(b/2)^2 would complete the square
(sign doesn't matter becaus when squareing, sign goes positive)