A rectangular garden has an area if

12a^2-5a-2m^2

A.) Write the area as the product of two binomials with integer coefficients

B.) the garden is to be completely enclosed by a path 1 m wide. find and simplify an expression for the area of the path

C.) the path is concrete, poured to a depth of 10 cm. calculate the volume in m^3 of concrete used if a=6

1 answer

I think you meant
12a^2 - 5a - 2 = (3a-2)(4a+1)

After the path, each dimension is increased by 2, so the new total area is

(3a-2+2)(4a+1+2) = (3a)(4a+3)
Now subtract the original area to get the area of the path:

(3a)(4a+3)-(3a-2)(4a+1)
now just simplify that

Finally, just plug in a, recalling that the volume

v = (a)(.10) m^3