What you can do is multiply 400*20= 8,000. From here, we know that 399*20 is just one less group of 20 than 400. Therefore, we can subtract (1*20) from 8,000 to get the final answer.
8000-20=7980
Hope this helps!
No because 24 hours would be from 3:20 to 3:20
3x+(x-2)=10
4x=12
x=12/4=3
y=x-2=3-2=1
so, x=3 and y=1
Answer: (3;1)
(y-4) (y-3)
you look at 12 and see what two factors of 12 add up to -7 and -4 times -3 is 12 and -4+-3 = -7