Six machines, each working at the same constant rate, together can complete a certain job in 12 days. how many additional machines, each working at the same constant rate, will be needed to complete the job in 8 days? a. 2
b. 3
c. 4
d. 6
e. 8

B

Step-by-step explanation:

6 machines complete the job in 12 days;

the more machine you have faster the job will be done, inverse proportion

6 machines ---  12 days

x machines -- 8 days

you reduce the number of days by a factor of 1.5 (12/1.5)

sou you hvae to increase the number of machines by 1.5

6 x 1.5 = 9, so you will need 3 additional machines

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct