Step 1: x²-15=2x
step 2: x²-2x-15=0
step 3: (x-5)(x+3)=0
step 4: x-5=0 or x+3=0
step 5: x=5 of x=-3
Answer: 11.4
Step-by-step explanation:
change to numbers 
simplify 
Answer:
Kent is making a scale model of his favorite train. The actual train is 12 feet long and 4 feet wide. Kent wants his model to be 6 inches in length. Which would if he uses the same ratio?
Step-by-step explanation:
Kent is making a scale model of his favorite train. The actual train is 12 feet long and 4 feet wide. Kent wants his model to be 6 inches in length. Which would be the width if he uses the same ratio?
binomial(16 + 7, 16) 2^(-(16 + 7)) = ((16 + 7)!)/(16! 7! 2^(16 + 7)) = 245157/8388608 ≈ 0.02922 ≈ 1/34.22
(assuming children are independent and male and female are equally likely)
| probability
less than 16 boys | 0.9534
16 or less boys | 0.9827
more than 16 boys | 0.01734
16 or more boys | 0.04657
fraction of boys | 16/(16 + 7) ≈ 0.695652
fraction of girls | 7/(16 + 7) ≈ 0.304348
expected value | 11.5
standard deviation | 2.398
variance | 5.75
11.5
We could do it with algebra. But we can also do it the long way, which is
shorter than the algebraic way.
The digit in the tens place is 3 times the digit in the units place.
So the number MUST be
31, or
62, or
93 .
It can't be anything else.
Now here they are again, with the reverse of each one:
31 . . . 13 The new number is 18 less.
62 . . . 26 The new number is 36 less.
93 . . . 39 The new number is 54 less.
Obviously, the original number is 62.
