JAMB Mathematics Past Questions & Answers - Page 273

1,361.

Simplify \(\frac{1}{p}\) - \(\frac{1}{q}\) \(\div\) \(\frac{p}{q}\) - \(\frac{q}{p}\)

A.

\(\frac{1}{p - q}\)

B.

\(\frac{-1}{p + q}\)

C.

\(\frac{1}{pq}\)

D.

\(\frac{1}{pq(p - q)}\)

Correct answer is B

\(\frac{1}{p}\) - \(\frac{1}{q}\) \(\div\) \(\frac{p}{q}\) - \(\frac{q}{p}\) = \(\frac{q - p}{pq}\) ÷ \(\frac{p^2 - q^2}{pq}\)

\(\frac{q - p}{pq}\) x \(\frac{pq}{p^2q^2}\) = \(\frac{q - p}{p^2 - q^2}\)

\(\frac{-(p - q)}{(p + q)(p - q)}\)

= \(\frac{-1}{p + q}\)

1,362.

Divide the expression x3 + 7x2 - x - 7 by -1 + x2

A.

-x3 + 7x2 - x - 7

B.

-x3 = 7x + 7

C.

x - 7

D.

x + 7

Correct answer is D

No explanation has been provided for this answer.

1,363.

If the function f is defined by f(x + 2) = 2x\(^2\) + 7x - 5, find f(-1)

A.

-10

B.

-8

C.

4

D.

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) = \(2(-3)^{2} + 7(-3) - 5\)

= \(18 - 21 - 5 = -8\)

1,364.

Solve the following equation (3x - 2)(5x - 4) = (3x - 2)2

A.

\(\frac{-2}{3}\), 1

B.

1

C.

\(\frac{2}{3}\), 1

D.

\(\frac{2}{3}\), \(\frac{4}{5}\)

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 \(\frac{2}{3}\)

1,365.

Solve the following simultaneous equation for x. x2 + y - 5 = 0, y - 7x + 3 = 0

A.

-2, 4

B.

2, 4

C.

-1,8

D.

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