Question

6. Show that (5x + 3)2 – 60x = (5x – 3 )2
7. If 24 workers can build a wall in 30 hours, how many workers will be required to do
the same work in 48 hours?

Answer 1

Answer:

1.answer =1/5

2.answer=15

Step-by-step explanation:

see I am not sure for answer 1. but answer 2 is permanently right

Answer 2

Step-by-step explanation:

6. (5x+3)²-60x=(5x-3)²

= (5x)²+(3)²+2×5x×3-60x= (5x)²+(3)²-2×5x×3

=25x²+9+30x²-60x=25x²+9-30x

=0

7. The fraction of work done each hour by one worker is 1/24x 1/30 = 1/720

In 30 hours one worker could do 48 x 1/720 = 1/15 of the work, so you will need 15 workers to do the work in 48 hours.