Ax^2+bx=c
REMEMBER THIS
ok
first, make sure that a is 1
done
now take 1/2 of b and square it
-18/2=-9, (-9)^2=81
add that to both sides
x²-18x+81=19+81
x²-18x+81=99
factor perfect square
(x-9)²=100
square root both sides
don't forget positive and negative root
x-9=10
x-9=-10
ad 9 to both sides
x=19
x=-1
answer is -1; 19
2nd choice is answer
The geometric sequence is a sequence in which the proceeding number is equal to the preceeding number multiplied by a ratio. The expression that represents this sequence is an = a1*r^(n-1) where r is the ratio and n is an integer. This type of formula is exponential
10 for red and blue together and 5 for green and yellow together