Answer:
10 .
how i got this calculator
Answer:
A) 991=43x+475
B) 12 hours
Step-by-step explanation:
Ok
2x + y - z = 7
-2y +3z = -15
x + 2y - 5z = 17
combine 2nd 3rd
x - 2z = 2
x = 2z + 2
double first statement
4x + 2y - 2z = 14
combine with second statement
4x + z = -1
substitute 2z + 2 for x
8z + 8 + z = -1
combine like terms
9z + 8 = -1
sub 8 from both sides
9z = -9
divide both sides by 9
z = -1
substitute -1 for z in second statement
-2y - 3 = -15
add 3 to both sides
-2y = -12
divide both sides by -2
y = 6
substitute -1 for z into the fifth statement
x = -2 + 2
x = 0
Almost 60 years after taking my last math class, I discovered
how to turn a repeating decimal into its equivalent fraction.
-- Take the set of digits that repeats, no matter how many digits there are.
Write them as the numerator of a fraction.
-- For the denominator, write the same number of '9's.
-- If it's possible and you feel like it, simplify (reduce) the fraction.
You have 0.023 with the 23 (two digits) repeating forever.
-- Write the 23 (two digits) as the numerator.
-- Write 99 (two digits) as the denominator.
Now you have the fraction 23 / 99 . It can't be reduced.
You actually had 0.0... before the repeating part. That just
means that the fraction has been divided by 10. The real
equivalent fraction is 23 / 990 . (Which also can't be reduced.)
After so many years not knowing how to do it, this still blows my mind.
Just now, I punched " 23/990 "into my calculator, and stared in wonder
and amazement when " 0.023232323 " came up.
