Question

An apple orchard contains 126 trees. The number of trees in each row is 4 less than twice the number of rows. Give possible expression for number of rows and the number of trees per row. If area of orchard is (x^2+12x+27) and width is (x+9), find the length. *​

Answer 1

Answer:

Step-by-step explanation:

Let R = number of Rows

Let T = number of Trees per row

We are told that T = 2R -4

We are told that the total trees is 126

Total trees = R * T

Plug in our data:

126 = R (2R -4)

126 = 2R^2 - 4R

Subtract 126 from both sides to set the equation equal to zero.

126 - 126 = 2R^2 - 4R - 126

0 = 2R^2 - 4 R - 126

Divide both sides by 2 to get rid of the coefficient of the 2R^2

0 = R^2 - 2R - 63

0 = (R-9)(R + 7)

R = 9 or R = -7

Obviously, the negative will not work.

Plug in to check.

126 = R * (2R - 4)

126 = 9 * (2*9-4)

126 = 9 * (18-4)

126 = 9* (14)

126 = 126