I'm not sure exactly which type you are meaning since there are four types of expansions, but depending on which specific type here are your answers! :)
Answer: There is a difference between rote counting and rational counting. Rote counting involves the memorization of numbers. Rational counting tells children "how many there are." For children to count rationally, they need to demonstrate one-to-one correspondence.
85 x 0.07 = 5.95
Total = 85 + 5.95 = 90.95%
So first you have to find the perfect square that matches up with x^2 + 6x
so half of 6, and square it. your perfect square is 9
x^2 + 6x + 9 = 7 + 9
then, condense the left side of the equation into a squared binomial:
(x + 3)^2 = 16
take the square root of both sides:
x + 3 = ± √16
therefore:
x + 3 = ± 4
x = - 3 ± 4
so your solution set is:
x = 1, -7