How good are you with figures and formulas? Find out with these Mathematics past questions and answers. This Test is useful for both job aptitude test candidates and students preparing for JAMB, WAEC, NECO or Post UTME.
If the function f is defined by f(x + 2) = 2x\(^2\) + 7x - 5, find f(-1)
-10
-8
4
10
Correct answer is B
f(x + 2) = f(-1)
f(-1) is gotten when x = -3.
\(2x^{2} + 7x - 5\) at x = -3.
f(-1) = \(2(-3)^{2} + 7(-3) - 5\)
= \(18 - 21 - 5 = -8\)
Solve the following equation (3x - 2)(5x - 4) = (3x - 2)2
\(\frac{-2}{3}\), 1
1
\(\frac{2}{3}\), 1
\(\frac{2}{3}\), \(\frac{4}{5}\)
Correct answer is C
(3x - 2)(5x - 4) = (3x - 2)2 = 5x2 - 22x + 6
= 9x2 = 12x + 4
6x2 - 10x + 4 = 0
6x2 - 6x - 4x + 4 = 0
6x(x - 1) -4(x - 1) = (6x - 4)(x -1) = 0
x = 1 or \(\frac{2}{3}\)
Solve the following simultaneous equation for x. x2 + y - 5 = 0, y - 7x + 3 = 0
-2, 4
2, 4
-1,8
1, -8
Correct answer is D
x2 + y - 5 = 0.....(i)
y - 7x + 3 = 0.........(ii)
y = 7x - 3, substituting the value of y in equation (i)
x2 + (7x - 3) - 5 = 0
x2 + 7x + 3 = 0
(x + 8)(x - 1) = 0
x = -8 or 1
Evaluate (x + \(\frac{1}{x}\) + 1)2 - (x + \(\frac{1}{x}\) + 1)2
4x2
(\(\frac{2}{x}\) + 2)2
4
4(1 + x)
Correct answer is D
(x + \(\frac{1}{x}\) + 1)2 - (x + \(\frac{1}{x}\) + 1)2
= (x + \(\frac{1}{x}\) + 1 + x + \(\frac{-1}{x}\) - 1)(x - \(\frac{1}{x}\) + 1 - x + \(\frac{1}{x}\) + 1)
= (2x) (2 + \(\frac{2}{x}\)) = 2x x 2(1 + \(\frac{1}{x}\))
4x (1 + \(\frac{1}{x}\)) = 4x + 4
= 4(1 + x)
Which of the following is a factor of 15 + 7x - 2x2
x + 3
x - 3
x - 5
x + 5
Correct answer is C
Factorize 15 + 7x - 2x2
(5 - x)(3 + 2x); suppose 15 + 7x = 2x2 = 0
∴ (5 - x)(3 + 2x) = 0
x = 5 or x = -\(\frac{3}{2}\)
Since 5 is a root, then (x - 5) is a factor