Need help with mark brainlist. Nam worked on a job for 10 days. On each of the last 2 days, he worked 2 hours more than the mean number of hours he worked per day during the first 8 days. If he worked 69 hours in all, how many hours did he work during the last 2 days together?

17 hours

Step-by-step explanation:

Given that On each of the last 2 days, he worked 2 hours more than the mean number of hours he worked per day during the first 8 days. That is he worked additional 4 hours for the two days.

Let the total hours for the 8 days = E

The mean = E/8 = 0.125E

For the two last days, he worked

( 0.125E + 2 ) × 2 = 0.25E + 4

If he worked 69 hours in all, then

E + 0.25E + 4 = 69

Collect the like terms

1.25E = 69 - 4

1.25E = 65

E = 65/1.25

E = 52.

Now find the mean of the first 8 days

Mean = 52 / 8 = 6.5 hours

Nam works during the last 2 days together for:

(6.5 + 2)×2

8.5 × 2 = 17 hours

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15