7. If 10 men can build a house in 90 days, how many men can build a home in 20 days?
A) 18
B) 36
C) 45
D) 180

2.222

Step-by-step explanation:

10 : 90

x : 20

cross multiply

10 x 20 =  90x

200 = 90x

both divide by 90

x = 2.2222

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