Since if he gets the driveway done in 20 minutes he gets 1/20th of the driveway done in 1 minute (if x=20 then x/20=1 by dividing both sides by 20) and if his brother gets 1/12th of the driveway done in one minute, then if t represents the time it takes to shovel the driveway, t/20+t/12=1 driveway shoveled as 1/20+1/12=amount they can do in 1 minute, so t/20+t/12 is how much they can do in t minutes. Multiplying both sides by 20*12=240, we get 12t+20t=32t=240. Dividing both sides by 32, we get 240/32=7.5 minutes to shovel the driveway.
Answer:
The answer to your question is below
Step-by-step explanation:
Number 9.
To find x use the law of sines
sin x / 8 = sin 95 / 12
Solve for sin x
sin x = 8 sin 95 / 12
sin x = 0.664
x = 41.6°
Number 10
To find x use law of cosines
x² = 6² + 8² - 2(6)(8)cos100
x² = 36 + 64 - 96(-0.174)
x² = 100 + 16.67
x² = 116.67
x = 10.80
The answer is to 12 x 12 is 1,524