Answer:
Total of 9 lengths of 4 inches can be taken out from a board of 3 feet
Step-by-step explanation:
length of board in feet = 3 ft
As
1 ft = 12 inches
So
Length of board in inch = 
= 36 inches
Let no of 4 inches length be = x
The equation become

Total of 9 lengths of 4 inches can be taken out from a board of 3 feet
2x^2+20x=-38 divide both sides by 2
x^2+10x=-19, halve the linear coefficient, square it, than add that value to both sides of the equation, in this case add (10/2)^2=25...
x^2+10x+25=6 now the left side is a perfect square
(x+5)^2=6 take the square root of both sides
x+5=±√6 subtract 5 from both sides
x=-5±√6 (so answer c.)
Answer:
a
Step-by-step explanation:
bc proportions
Step-by-step explanation:
Difference of Squares: a² - b² = (a + b)(a - b)
(x² - 16) / (x - 4)
= [(x + 4)(x - 4)] / (x - 4)
= x + 4, where x =/= 4.