\(\frac{7}{18}\)x
\(\frac{11}{20}\)x
\(\frac{4}{15}\)x
\(\frac{5}{18}\)x
Correct answer is D
x kmh-1 = y ms-1
\(\frac{x km}{1 hr}\) = y ms-1
\(x \times \frac{1km}{1hr}\) = y ms-1
\(x \times \frac{1000m}{60 \times 60s}\) = y ms-1
\(x \times \frac{1000}{3600} \frac{m}{s}\) = y ms-1
\(x \times \frac{5}{18} ms^{-1}\)
\(x \times \frac{5}{18} ms^{-1}\) = y ms-1
y = \(\frac{5}{18}\)x
If x2 + kx + \(\frac{16}{9}\) is a perfect square, find the value of k
\(\frac{8}{3}\)
\(\frac{7}{3}\)
\(\frac{5}{3}\)
\(\frac{2}{3}\)
Correct answer is A
x2 + kx + \(\frac{16}{9}\); Perfect square
But, b2 - 4ac = 0, for a perfect square
where a - 1; b = k; c = \(\frac{16}{9}\)
k2 - 4(1) x \(\frac{16}{9}\) = 0
k2 - \(\frac{64}{9}\) = 0
k2 = \(\frac{64}{9}\)
k = \(\sqrt{\frac{64}{9}}\)
k = \(\frac{8}{3}\)
If the sum of the roots of the equation (x - p)(2x + 1) = 0 is 1, find the value of x
1\(\frac{1}{2}\)
\(\frac{1}{2}\)
-\(\frac{3}{2}\)
-1\(\frac{1}{2}\)
Correct answer is A
(x - p)(2x + 1) = 0
2x2 + x - 2px - p = 0
2x2 + x (1 - 2p) - p = 0
2x2 - (2p - 1)x - p = 0
divide through by 2
x2 - \(\frac{(2p - 1)}{2}\)x - \(\frac{p}{2}\) = 0
compare to x2 - (sum of roots)x + product of roots = 0
sum of roots = \(\frac{2p - 1}{2}\)
But sum of roots = 1
Given; \(\frac{2p - 1}{2}\) = 1
2p - 1 = 2 x 1
2p - 1 = 2
2p = 2 + 1 = 3
p = \(\frac{3}{2}\)
p = 1\(\frac{1}{2}\)
2
3
4
5
Correct answer is A
5 1 6 2seven
-2 6 4 4seven
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2 2 1 5
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the missing number is 2
What is the value of x when y = 5? y = \(\frac{1}{2}\) x + 1
8
9
10
11
Correct answer is A
when y = 5; x = ?; y = \(\frac{1}{2}\)x + 1
5 = \(\frac{1}{2}\)x + 1
5 - 1 = \(\frac{1}{2}\)x
4 = \(\frac{1}{2}\)x
x = 4 x 2
x = 8