6, a, b, 12
We know that the common difference is the same between each term.
Therefore, we can set up an equation to solve for the common difference:
a - 6 = b - a
a - 6 = 12 - b
Subtracting the two equations:
b - a = 12 - b
2b = 18
b = 9
Substituting b into the first equation:
a - 6 = 9
a = 15
Therefore, the common difference is 3.
Show all work
If the 1at term of an ap is 6,and the 4th term is 12 ,find the common difference
Form the sequence
2 answers
WRONG AGAIN!!!
simpler way:
a = 6
a + 3d = 12 , but a = 6
6 + 3d = 12
3d = 6
d = 2
check: terms would be
6, 8, 10 , 12
the bot's terms would be 6, 9, 12, 15, clearly a contradiction
simpler way:
a = 6
a + 3d = 12 , but a = 6
6 + 3d = 12
3d = 6
d = 2
check: terms would be
6, 8, 10 , 12
the bot's terms would be 6, 9, 12, 15, clearly a contradiction