Just calculate second term - first term = -4 - (-15)
Answer:
a3 + b3 = -7
Step-by-step explanation:
When the sequence is A.P
a1 =4 and a2= -2
Common difference,d = a2 - a1
= -2 - 4
d = -6
a3 = third term
a3 = a1 + 2d
= 4 + 2(-6)
= 4 - 12
= -8
a3 = -8
When the sequence is geometric
a1 =4 and a2= -2
Common ratio, r = a2/a1
= -2/4
r = -1/2
Or
r = -0.5
b3 = third term
b3 = ar²
= 4 * (-1/2)²
= 4 * 1/4
= 4/4
= 1
b3 = 1
a3 + b3 = -8 + 1
= -7
a3 + b3 = -7
Answer:
x=1+/-4i
Step-by-step explanation:
(x+1)/3-(2x-1)/x=-1
find the common denominator,
in this case, it's going to be 3x.
(x^2+x)/3x-(6x-3)/3x=-1
(x^2+x-6x+3)/3x=-1
x^2-5x+3=-3x
x^2-5x-(-3x)+3=0
x^2-5x+3x+3=0
x^2-2x+3=0
apply the quadratic formula in order to find the roots for x.
Since ax^2+bx+c=0, in this case,
a=1, b=-2, c=3
--------------------------
x=(-b+/-sqrt(b^2-4ac))/2a
x=(2+/-sqrt(4-12))/2
x=(2+/-8i)/2
x=1+/-4i