(x + 2a)(x + 1)
(x + 2a)(x - 1)
(x2 - 1)(x - a)
(x + 2)(x + a)
Correct answer is D
x2+2a+ax+2x
x2+2a+ax+2x
x(x+2)+a(x+2)
(x+2)(x+a)
Find all real numbers x which satisfy the inequality 13(x + 1) - 1 > 15(x + 4)
x < 11
x < -1
x > 6
x > 11
Correct answer is D
13(x + 1) - 1 > 15(x + 4)
= x+13 - 1 > x+45
x+13 - x+45 - 1 > 0
= 5x+5−3x−1215
= 2x - 7 > 15
= 2x > 22
= x > 11
If y = xx−3 + xx+4 find y when x = -2
-35
35
-75
25
Correct answer is A
y = xx−3 + xx+4 when x = -2
y = −2−5 + (−2)−2+4
= 25 + −22
= 4−1010
= −610
= -35
Factorize completely 8a + 125ax3
(2a + 5x2)(4 + 26ax)
a(2 + 5x)(4 - 10x + 25x2)
(2a + 5x)(4 - 10ax + 25x2)
a(2 + 5x)(4 + 10ax + 25x2)
Correct answer is B
8a+125ax3=(23)a+53ax3
= a(23+53x3)
∴a[23+(5x)3]
a3+b3=(a+b)(a2−ab+b2)
∴ a(23+(5x)3)
= a(2+5x)(4−10x+25x2)
If x varies directly as y3 and x = 2 when y = 1, find x when y = 5
2
10
125
250
Correct answer is D
x α y3
x = ky3
k = xy3
when x = 2, y = 1
k = 2
Thus x = 2y3 - equation of variation
= 2(5)3
= 250