Answer:
f(- 7) = - 57
Step-by-step explanation:
To evaluate f(- 7) substitute x = - 7 into f(x) = 7x - 8, since condition is
f(x) = 7x - 8 for x ≥ - 7, thus
f(- 7) = 7(- 7) - 8 = - 49 - 8 = - 57
Answer:
number of kilometers travelled by cavalier-86.4
he used 6litres for the journey. take number of kilometers divide by number of litres
86.4/6=14.4
The answer is 867.
3^3 = 27
27•32 + 12/4
864 + 3 = 867
Answer:
n(n+1)(n+5)/3
Step-by-step explanation:
there is no value, as we don't know n.
but we can create a summary formula/ function definition :
this is the sum for k = 1 to n of k×(k+3)
k×(k+3) = k² + 3k
so, the overall sum splits into the sum of k² for k=1 to n, and the sum of 3k for k=1 to n.
and the sum of 3k is 3 times the sum of k for k=1 to n.
Σk² for k=1 to n = [n(n+1)(2n+1)]/6
Σk for k=1 to n = n(n+1)/2
3×Σk for k=1 to n = 3×n(n+1)/2
so, we have a function formula
n(n+1)(2n+1)/6 + 3n(n+1)/2 = n(n+1)(2n+1)/6 + 9n(n+1)/6 =
= n(n+1)(2n+1+9)/6 = n(n+1)(2n+10)/6 = n(n+1)(n+5)/3
