P varies inversely as the square of W. When W = 4, P = 9. Find the value of P when W = 9
729/16
6
4
16/9
4/3
Correct answer is D
P α 1/w2; P = K/W2
9 = K/42; 9 = K/16
K = 9 x 16 = 144
P = K/W2; when w = 9
P = 144/92 = 144/81 = 16/9
Make q the subject of the relation t = √(pq/r - r\(^2\)q)
q = \(\frac{rt^2}{(p - r^3)}\)
q = \(\frac{t^2}{(p - r^2)}\)
q = \(\frac{rt}{(p - r^3)}\)
q = \(\frac{(p - r^3)}{rt^2}\)
q = rt\(^2\)(p - r\(^3\))
Correct answer is A
t = √pq/r - r\(^2\)q
multiply both sides by the L.C.M, r
r\(^2\) = pq - qr\(^3\)
collect like terms on the RHS
q(p - r3) = rt\(^2\)
q = \(\frac{rt^2}{(p - r^3)}\)
Solve the equations: 4x -y = 11; 5x + 2y = 4.
x = 6, y = 13
x = -2, y = -3
x = -2, y = 3
x = 2, y = -3
x = 2, y = 3.
Correct answer is D
4x - y = 11....(1) x 2 8x - 2y = 22....(3)
5x + 12y = 4....(2) x 1 5x + 2y = 4....(4)
add eqn (3) and (4)
13x = 26
x = 2
4(2) - y = 11 ⟹⟹ y = 8 - 11
y = -3.
Which of the following equations has its roots as 4 and -5?
x2 + 4x - 20 = 0
x2 + x + 20 = 0
x2 - x + 20 = 0
x2 + x - 20 = 0
x2 - x - 20 = 0
Correct answer is D
(x - 4)(x + 5) = 0
x\(^2\) + 5x - 4x - 20 = 0
x\(^2\) + x - 20 = 0
Solve me equation: 2/3 (x + 5) = 1/4(5x - 3)
11/7
18/23
3
43/7
7
Correct answer is E
2/3 (x + 5) = 1/4(5x - 3)
8x + 40 = 15x - 9
-7x = -49
x = 7