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WAEC Mathematics Past Questions & Answers - Page 302

1,506.

Write as a single fraction 11x+21+x

A.

x+31x2

B.

3x(1x)2

C.

3x1+x2

D.

3x(1+x)2

E.

3x1x2

Correct answer is E

11x+21+x

= (1+x)+2(1x)(1x)(1+x)

= 1+x+22x1x2

= 3x1x2

1,507.

Construct a quadratic equation whose roots are 12 and 2.

A.

3x2-3x+2=0

B.

3x2+3x-2=0

C.

2x2+3x-2=0

D.

2x2-3x+2=0

E.

2x2-3x-2=0

Correct answer is E

If x = 12 and 2; then

x+12=0 and x2=0

(x+12)(x2)=0

x22x+12x1=0

x232x1=0

2x23x2=0

1,508.

Factorize the expression 2y2 + xy - 3x2

A.

2y (y + x) - 3x2

B.

(2y - x)(2y + x)

C.

(3x - 2y(x - y)

D.

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

E.

(x – y)(2y + 3x)

Correct answer is D

2y2 + xy - 3x2

2y2 + 3xy - 2xy - 3x2

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

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

1,509.

Evaluate log1025+log1032log108

A.

0.2

B.

2

C.

100

D.

409

E.

490

Correct answer is B

log1025+log1032log108

= log10(25×328)

= log10100

= 2

1,510.

Simplify: (1681)14

A.

8/27

B.

1/3

C.

4/9

D.

2/3

E.

-4/3

Correct answer is D

(1681)14

= ((23)4)14

= 23