Respuesta :
Answer:
x = 9
Step-by-step explanation:
since the terms are in AP then there is a common difference between consecutive terms, that is
a₂ - a₁ = a₃ - a₂ ( substitute values )
x - 7 = 11 - x ( add x to both sides )
2x - 7 = 11 ( add 7 to both sides )
2x = 18 ( divide both sides by 2 )
x = 9
Answer:
9
Step-by-step explanation:
The nth term of an AP has the formular
a+ ( n - 1 ) d
a = first term
n = number of terms
d = common difference
common difference d = T2 - T1 0r T3 - T2
d = x - 7 or 11 - x
Therefore,
3rd term
a + (3 - 1)d
a + 2d
Hence,
7 +2d = 11
substitute the value of d above
7 + 2 (x -7) = 11
7 + 2x - 14 = 11
2x = 11 +14 -7
2x = 18
dividing bothsides by 2
x = 18/2
x = 9