In general, nCr = n! / r! (n-r)!
Here, 7C3 = 7! / 3!(7-3)!
=7 x 6 x 5 x 4 x 3 x 2 x 1 /3 x 2 x 1 ( 4 x 3 x 2 x 1)
=7x6x5x4 / 4x3x2
=7x5x6x4 / 24
=35x24 / 24
=35
Let's say H is Howard and E is Erin and L is Lee. Since Lee downloaded 16 songs L=16. If Lee downloaded 3 more songs than Howard then H+3=16 so H=13. Is howard downloaded 6 more songs than Erin that means E+6=15. Finally E= 9
Answer:
letterA
Step-by-step explanation:
ODAL my answer is answer for you
A line perpendicular to the two parallel lines would create 8 right angles.
We have f(x) = 0;
Then x^2 - 1 - 2x - 2 = 0;
(x - 1)(x + 1) - 2(x + 1) = 0;
(x + 1)(x - 1 - 2) = 0;
(x + 1)(x - 3) = 0;
x + 1 = 0 or x - 3 = 0;
x = -1 or x = 3;
The zeroes of f are -1 and 3.