If y∝1√x and x = 16 when y = 2, find x when y = 24
19
16
13
23
Correct answer is A
y∝1√x
y=k√x
When x = 16, y = 2.
2=k√16⟹2=k4
k=8
y=8√x
When y = 24,
24=8√x
√x=824=13
∴
x = \frac{1}{9}
Subtract (-y + 3x + 5z) from (4y - x - 2z)
5y - 4x - 7z
3y + 2x + 3z
-5y + 4x + 7z
2x - 5y + 3z
Correct answer is A
(4y - x - 2z) - (-y + 3x + 5z)
= 4y + y - x - 3x - 2z - 5z
= 5y - 4x - 7z
y = -1
y = 1
y = 3
y = -3
Correct answer is D
Let the straight line PQ = y
2x^2 - 5x - 1 - y = 2x^2 - 5x + 2
y = 2x^2 - 5x - 1 - 2x^2 + 5x - 2
y = -3
which of the following is not quadratic expression?
y = 2x^2 - 5x
y=x(x-5)
y = x^2 - 5
y = 5(x-1)
Correct answer is D
A quadratic equation is an equation of the second order. The highest power in the equation is 2.
If 2x^2 + kx - 14 = (x+2)(2x-7), find the value of K
-3
5
9
11
Correct answer is A
2x^2 + kx - 14 = (x+2)(2x-7)\\
∴2x^2 + kx - 14 = 2x^2 - 3x - 14
equating coefficient K = -3