JAMB Mathematics Past Questions & Answers - Page 343

1,711.

Evaluate the inequality \(\frac{x}{2} + \frac{3}{4} \leq \frac{5x}{6} - \frac{7}{12}\)

A.

\(x \geq 4\)

B.

\(x \leq 3\)

C.

\(x \geq -3\)

D.

\(x \leq -4\)

Correct answer is A

\(\frac{x}{2} + \frac{3}{4} \leq \frac{5x}{6} - \frac{7}{12}\)

\(12\frac{x}{2} + 12\frac{3}{4} \leq 12\frac{5x}{6} - 12\frac{7}{12}\)

6x + 9 \(\leq\) 10x - 7

6x - 10x \(\leq\) - 7 - 9

-4x \(\leq\) -16

-4x/-4 \(\geq\) -16/-4

x \(\geq\) 4

1,712.

What is the solution of \(\frac{x - 5}{x + 3} < -1\)?

A.

-3 < x < 1

B.

x < -3 or x > 1

C.

-3 < x < 5

D.

x < -3 or x > 5

Correct answer is A

Consider the range -3 < x < -1

= { -2, -1, 0}, for instance

When x = -2,

\(\frac{-2 - 5}{-2 + 3} < -1\)

\(\frac{-7}{1} < -1\)

When x = -1,

\(\frac{-1 - 5}{-1 + 3} < -1\)

\(\frac{-6}{2} < -1\)

= -3 < -1

When x = 0,

\(\frac{0 - 5}{0 + 3} < -1\)

\(\frac{- 5}{3} < -1\)

Hence -3 < x < 1

1,713.

Factorize 2y2 - 15xy + 18x2

A.

(2y - 3x) (y + 6x)

B.

(2y - 3x) (y - 6x)

C.

(2y + 3x) (y - 6x)

D.

(3y + 2x) (y - 6x)

Correct answer is B

2y2 - 15xy + 18x2

2y2 - 12xy - 3xy + 18x2

2y(y - 6x) - 3x(y - 6x)

(2y - 3x) (y - 6x)

1,714.

If gt2 - k - w = 0, make g the subject of the formula

A.

\(\frac{k + w}{t^2}\)

B.

\(\frac{k - w}{t^2}\)

C.

\(\frac{k + w}{t}\)

D.

\(\frac{k - w}{t}\)

Correct answer is A

gt2 - k - w = 0

gt2 = k + w

\(g = \frac{k + w}{t^2}\)

1,715.

If P = {1,2,3,4,5} and P \(\cup\) Q = {1,2,3,4,5,6,7}, list the elements in Q

A.

{6}

B.

{7}

C.

{6,7}

D.

{5,6}

Correct answer is C

Q = (P \(\cup\) Q) - P
{6,7}