Answer:
3 and 7
Step-by-step explanation:
You know from your multiplication tables that ...
21 = 1×21 = 3×7
There are no other factorizations of 21 using integers. You may notice that the sums of these factors are ...
1+21 = 22
3+7 = 10 . . . . . . this is the pair of numbers you are looking for
The two numbers are 3 and 7.
Answer: A
Step-by-step explanation:
c - 12 > -16
c > -4
A
It is asking you to find the sum of k^2 - 1 from k=1 to k=4. Since that is only 4 numbers, calculating the sum by hand wouldn’t be that bad.
(1^2 - 1) + (2^2 - 1) + (3^2 - 1) + (4^2 - 1) = 26
The easier way to find the sum is to use a few simple formulas.
When we have a term that is just a constant c, the formula is c*n.
When we have a variable k, the formula is k*n*(n+1)/2.
When we have a squared variable, the formula is k*n*(n+1)*(2n+1)/6.
In this case, we have a squared variable k^2 and a constant of -1.
So plug in n=4 to the formulas:
4*5*9/6 - 1*4 = 26
The answer is 26
Answer:
B. 3x^2 - 2x - 1.
Step-by-step explanation:
(f + g)x = f(x) + g(x)
= -4x + 3 + 3x^2 + 2x - 4
Adding like terms we get the answer:
= 3x^2 - 2x - 1.
