Find the roots of the equation 10x2 - 13x - 3 = 0
x = 35 or -12
x = 310 or -1
x = 310 or 1
x = 15 or −32
x = -15 or 32
Correct answer is E
10x2 - 13x - 3 = 0 = 10x2 - 15x + 2x - 3 = 0
5x(2x - 3) + 2x - 3 = 0
= (5x + 1)(2x - 3) = 0
5x + 1 = 0 or 2x - 3 = 0
x = -15 or 32
List all integer values of x satisfying the inequality -1 < 2x - 5 ≤ 5
<2, 3, 4, 5
3, 4, 5
2, 3, 4
3, 4
Correct answer is B
−1<2x−5≤5
⟹−1+5<2x−5+5≤5+5
4<2x≤10
⟹2<x≤5
= 3, 4, 5.
The median of the set of numbers 4, 9, 4, 13, 7, 14, 10, 17 is
13
7
192
394
10
Correct answer is C
Rearranging in increasing order 4, 4, 7, 9, 10, 13, 14, 17, the
median = (9+10)2
= 192
When a dealer sells a bicycle for N81 he makes a profit of 80%. What did he pay for the bicycle?
N73
N74.52
N75
N87.48
N75.52
Correct answer is C
Profit = 8%
∴
108% = N81
100% = \frac{81}{108} \times 100
= \frac{8100}{108} = N75
Rationalize the denominator of the given expression \frac{\sqrt{1 + a} - \sqrt{a}}{1 + a + \sqrt{a}}
1 + 2a - 2\sqrt{a(1 + a)}
\sqrt{1(1 + a)}
2a - 2\sqrt{a(1 + a)}
1 + 2a - 2\sqrt{a + b}
Correct answer is A
\frac{\sqrt{1 + a} - \sqrt{a}}{1 + a + \sqrt{a}} = \frac{\sqrt{1 + a} - \sqrt{a}}{\sqrt{1 + a} + \sqrt{a}} x \frac{\sqrt{1 + a} - \sqrt{a}}{\sqrt{1 + a} - \sqrt{a}}
= \frac{\sqrt{1 + a + a}}{1 + a - a}
= 2a + a(1 + a)
= 1 + 2a - 2\sqrt{a(1 + a)}