Calculati urmatoarele sume 1+2++80. 2+4++100. 1+3+5++99. 3+7+11+15++43

(a)

1+2+3+..........+80

we can see that this is arithematic sequence

so, first term is

common difference is

total term is

now, we can find sum of nth term

now, we can plug values

and we get

...........Answer

(B)

2+4+6+.......+100

we can see that this is arithematic sequence

so, first term is

common difference is

total term is

now, we can find sum of nth term

now, we can plug values

and we get

..........Answer

(C)

1+3+5+...+99

we can see that this is arithematic sequence

so, first term is

common difference is

total term is

now, we can find sum of nth term

now, we can plug values

and we get

..........Answer

(D)

3+7+11+15+...+43

we can see that this is arithematic sequence

so, first term is

common difference is

total term is

now, we can find sum of nth term

now, we can plug values

and we get

..........Answer

the answer would be c:   ax + b = ax + c

step-by-step explanation:

the number of possible outcomes that do not show a 1 on the first spinner and show the number 4 on the second spinner is 2.

spinner 1 spinner 2

1                     1

1                     2

1                     3

1                     4

2                   1

2                   2

2                   3

2                   4   = not 1, and 4

3                   1

3                   2

3                   3

3                   4 = not 1, and 4

only 2 outcomes have passed the given condition.

step-by-step explanation: