If m * n = n - (m+2) for any real number m and n find the value of 3*(-5)?
-6
-8
-10
-12
Correct answer is C
m * n = n - (m+2)
= -5 - (3+2)
= -5-5
= -10
10
9
10/9
9/10
Correct answer is A
\(a=1, r=\frac{9}{10}\\
S_n = \frac{a}{1-r}\\
S_n = \frac{1}{1-\frac{9}{10}}\\
=1\div \frac{1}{10}\\
=1\times \frac{10}{1}\\
10\)
The sum of the first n terms of the arithmetic progression 5, 11, 17, 23, 29, 35, ... is?
n(3n - 0.5)
n(3n + 2)
n(3n + 2.5)
n(3n + 5)
Correct answer is B
a = 5, d = 6, n = n
Sn = n/2(2a + (n-1)d)
= n/2(2(5) + (n-1)6)
= n/2(10 + 6n-6)
= n/2(6n+4)
= 6n2/2 + 4n/2
= 32 + 2n
= n(3n + 2)
Find the range of values of x for which 3x - 7 \(\leq\) 0 and x + 5 > 0?
-5 < x < \(\frac{7}{3}\)
-5 \(\leq\) x \(\leq\) \(\frac{7}{3}\)
-5 < x \(\leq\) \(\frac{7}{3}\)
5 \(\leq\) x < \(\frac{7}{3}\)
Correct answer is C
3x - 7 \(\leq\) 0 and x + 5 > 0
3x \(\leq\) 7 and x > -5
x \(\leq\) \(\frac{7}{3}\)
∴ Range -5 < x \(\leq\) \(\frac{7}{3}\)
Determine the value of x for which (x\(^2\) - 1) > 0?
x < -1 or x > 1
-1 < x < 1
x > 0
x < -1
Correct answer is B
No explanation has been provided for this answer.