Advertisements
Advertisements
Question
If u, v, w, and x are in continued proportion, then prove that (2u+3x) : (3u+4x) : : (2u3+3v3) : (3u3+4v3)
Advertisements
Solution
`"u"/"v" = "v"/"w" = "w"/"x" = "a"`
w = ax
v = aw = a2x
u = av = a3x
LHS
`(2"u" + 3"x")/(3"u" + 4"x")`
`= (2"a"^3"x" + 3"x")/(3"a"^3"x" + 4"x")`
`= (2"a"^3 + 3)/(3"a"^3 + 4)`
RHS
`(2"u"^3 + 3"v"^3)/(3"u"^3 + 4"v"^3)`
`= (2"a"^9"x"^3 + 3"a"^6"x"^3)/(3"a"^9"x"^3 + 4"a"^6"x"^3)`
`= (2"a"^3 + 3)/(3"a"^3 + 4)`
LHS = RHS. Hence , proved.
APPEARS IN
RELATED QUESTIONS
Find the fourth proportional to 3a, 6a2 and 2ab2
Find the fourth proportion to the following:
3,5 and 15
If `a/b = c/d = r/f`, prove that `((a^2b^2 + c^2d^2 + e^2f^2)/(ab^3 + cd^3 + ef^3))^(3/2) = sqrt((ace)/(bdf)`
Find the third proportional to `5(1)/(4) and 7.`
Determine if the following ratio form a proportion:
25 cm : 1 m and Rs 40 : Rs 160
Show that the following numbers are in continued proportion:
16, 84, 441
If the cost of 14 m of cloth is Rs 1890, find the cost of 6 m of cloth.
Choose the correct answer from the given options :
The third proportional to `6(1)/(4)` and 5 is
Unequal masses will not balance on a fulcrum if they are at equal distance from it; one side will go up and the other side will go down.
Unequal masses will balance when the following proportion is true:
`("mass"1)/("length"2) = ("mass"2)/("length"1)`

Two children can be balanced on a seesaw when
`("mass"1)/("length"2) = ("mass"2)/("length"1)`. The child on the left and child on the right are balanced. What is the mass of the child on the right?

What is the term "d" called in the expression a : b :: c : d?
