Answer:
f(n) = -n^2 -3n +5
Step-by-step explanation:
Suppose the formula is ...
f(n) = an^2 +bn +c
Then we have ...
f(1) = 1 = a(1^2) +b(1) +c
f(2) = -5 = a(2^2) +b(2) +c
f(3) = -13 = a(3^2) +b(3) +c
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Here's a way to solve these equations.
Subtract the first equation from the second:
-6 = 3a +b . . . . . 4th equation
Subtract the second equation from the third:
-8 = 5a +b . . . . . 5th equation
Subtract the fourth equation from the fifth:
-2 = 2a
a = -1
Then substituting into the 4th equation to find b, we have ...
-6 = 3(-1) +b
-3 = b
and ...
1 = -1 +(-3) +c . . . . . substituting "a" and "b" into the first equation
5 = c
The formula is ...
f(n) = -n^2 -3n +5
Answer:
1.x=-4+ y/2 - z/2
2. X=-4-y-z
3. x=y/3-2/3
Step-by-step explanation:
Answer:
Step-by-step explanation:
you have a right triangle,
a^2+b^2=c^2
10^2=4^2+b^2
100=16+b^2
100-16=b^2
84=b^2
b=9.16
Factor the following:
x^2 - 4 x + 3
The factors of 3 that sum to -4 are -1 and -3. So, x^2 - 4 x + 3 = (x - 1) (x - 3):
Answer: (x - 1) (x - 3)
Answer:
Step-by-step explanation:
1 ) 2 + 7t [ there are no like terms , so no further simplifying ]
2) 6r + ( - 16 r )
= 6 r - 16 r [ both are like terms ]
= - 10 r
3) (3x + 2 ) + ( 2x - 4 )
= 3x + 2 + 2x - 4
= 3x + 2x - 4 + 2 [ arranging like terms together ]
= 5x - 2
4) (8 n² - 3 n + 6 ) + ( n - 2 )
= 8n² - 3n + 6 + n - 2
= 8n² - 3n + n + 6 - 2 [ bringing like terms together ]
= 8n² - 2n + 4
