Advertisements
Advertisements
Question
Make a the subject of the formula S = `"n"/(2){2"a" + ("n" - 1)"d"}`. Find a when S = 50, n = 10 and d = 2.
Advertisements
Solution
S = `"n"/(2){2"a" + ("n" - 1)"d"}`
⇒ 2S = n{2a + (n - 1)d}
⇒ `(2"s")/"n"` = 2a + (n - 1)d
⇒ `(2"s")/"n" - ("n" - 1)"d"` = 2a
⇒ `{"S"/"n" - (("n" - 1)"d")/(2)}` = a
Substituting S = 50, n = 10 and d = 2, we get
a = `{"S"/"n" - (("n" - 1)"d")/(2)}`
= `{50/10 - (9 xx 2)/(2)}`
= 5 - 9
= -4.
APPEARS IN
RELATED QUESTIONS
Make a the subject of formula S = `"ut" + (1)/(2)"at"^2`
Make y the subject of formula W = `"pq" + (1)/(2)"wy"^2`
Make R2 the subject of formula R2 = 4π(R12 - R22)
If V = pr2h and S = 2pr2 + 2prh, then express V in terms of S, p and r.
Make s the subject of the formula v2 = u2 + 2as. Find s when u = 3, a = 2 and v = 5.
Make y the subject of the formula x = `(1 - y^2)/(1 + y^2)`. Find y if x = `(3)/(5)`
Make x the subject of the formula a = `1 - (2"b")/("cx" - "b")`. Find x, when a = 5, b = 12 and
Make m the subject of the formula x = `"my"/(14 - "mt")`. Find m, when x = 6, y = 10 and t = 3.
Make g the subject of the formula v2 = u2 - 2gh. Find g, when v = 9.8, u = 41.5 and h = 25.4.
"The volume of a cylinder V is equal to the product of π and square of radius r and the height h". Express this statement as a formula. Make r the subject formula. Find r, when V = 44cm3, π = `(22)/(7)`, h = 14cm.
