The answer is 3. 20/2=10 10-7=3
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
Area of a triangle:
A (triangle )= 4 · 6 / 2 = 12 ft²
150 - 12 = 138 ft² ( the maximum area of the rectangle )
L = ?
W = 6 ft
A ( rectangle ) = L · W
L · 6 = 138
L = 138 : 6 = 23 ft.
Answer: the maximum length of the base of the rectangle he can build is 23 ft.
The common difference in this sequence is -16 because each number decreases by 16 from the last