Answer:
-2640
Step-by-step explanation:
5³ = 125
11³ = 1331
16³ = 4096
125 + 1331 = 1456
1456 - 4096 = -2640
Answer:
- 72
Step-by-step explanation:
Using the order of operations PEMDAS ( parenthesis, exponents, multiplication, division, addition, subtraction )
Given
3 - 15 × 5 ← perform multiplication
= 3 - 75
= - 72
You can use the butterfly method. Two numbers that equal A times C must also add up to B. A=1 B=-10 C=21. A times C is 21 and B is -10. Two numbers that multiply to 21 and add to -10 are -7 and -3. Factored form: ( x - 7 )( x - 3 ).
an = a1r^(n-1)
a5 = a1 r^(5-1)
-6 =a1 r^4
a2 = a1 r^(2-1)
-48 = a1 r
divide
-6 =a1 r^4
---------------- yields 1/8 = r^3 take the cube root or each side
-48 = a1 r 1/2 = r
an = a1r^(n-1)
an = a1 (1/2)^ (n-1)
-48 = a1 (1/2) ^1
divide by 1/2
-96 = a1
an = -96 (1/2)^ (n-1)
the sum
Sn = a1[(r^n - 1/(r - 1)]
S18 = -96 [( (1/2) ^17 -1/ (1/2 -1)]
=-96 [ (1/2) ^ 17 -1 /-1/2]
= 192 * [-131071/131072]
approximately -192
