If x varies directly as square root of y and x = 81 when y = 9, Find x when y = 179
2014
27
214
36
Correct answer is D
x α√y
x = k√y
81 = k√9
k = 813
= 27
therefore, x = 27√y
y = 179 = 169
x = 27 x √169
= 27 x 43
dividing 27 by 3
= 9 x 4
= 36
Solve for x and y respectively in the simultaneous equations -2x - 5y = 3. x + 3y = 0
-3, -9
9, -3
-9,3
3, -9
Correct answer is C
-2x -5y = 3 x + 3y = 0 x = -3y -2 (-3y) - 5y = -3 6y - 5y = 3 y = 3 but, x = -3y x = -3(3) x = -9 therefore, x = -9, y = 3
Factorize completely 9y2 - 16X2
(3y - 2x)(3y + 4x)
(3y + 4x)(3y + 4x)
(3y + 2x)(3y - 4x)
(3y - 4x)(3y + 4x)
Correct answer is D
9y2 - 16x2
= 32y2 - 42x2
= (3y - 4x)(3y +4x)
Find the remainder when X3 - 2X2 + 3X - 3 is divided by X2 + 1
2X - 1
X + 3
2X + 1
X - 3
Correct answer is A
X2 + 1 X−2√X3−2X2+3n−3
= −6X3+n−2X2+2X−3
= (−2X2−2)2X−1
Remainder is 2X - 1
Make R the subject of the formula if T = KR2+M3
√3T−KM
√3T−MK
√3T+KM
√3T−KM
Correct answer is B
T = KR2+M3
3T = KR2 + M
KR2 = 3T - M
R2 = 3T−MK
R = √3T−MK