2007 - WAEC Mathematics Past Questions and Answers - page 2

(3x^{2}-2y+z=3(3)^{2}-2(2)+4=27-4+4=27)

x + y = 2 --- eqn I
3x - 2y = 1 --- eqn II
Multiply eqn by 2
2x + 2y = 2 --- eqn III
Subtract eqn II from eqnI
5x = 5 => x = 1
Substitute 1 for x in eqn 1
1 + y = 2 => y = 1

(8^{x+1}=\frac{1}{4}<br /> 2^{3(x+1)}=2^{-2}\Rightarrow 3(x+1)=-2\Rightarrow 3x+3=-2<br /> 3x=-5\Rightarrow x=\frac{5}{3})

N75.00 x 110.25 = N8,268.75

(5^{2}=3^{2}+x^{2}<br /> 25-9=x^{2}<br /> 16=x^{2}\Rightarrow x=4.0)

(r=\frac{\theta \times l}{360^{\circ }}<br /> r=?, \theta =60^{\circ }), l = radius of the orginal sector of a circle = 14cm
(r=\frac{60\times 14}{360}=\frac{7}{3}=2\frac{1}{3}cm)

(tan \hspace{1mm}y = \frac{opp}{adj}=\frac{2}{3}\Rightarrow \frac{2}{3}=\frac{
LN}{MN}=\frac{4}{MN}<br /> ∴ MN = \frac{12}{2}=6<br /> Area \hspace{1mm}of \hspace{1mm}\Delta LMN = \frac{1}{2}\times MN\times LN=\frac{1}{2}\times 6\times 4=12cm)

2³ x 3 x 5²

2 x 3² x 5

2² x 3³ x 5

The L.C.M = 2² x 3³ x 5²

(\frac{0.3 \times 10^5}{0.4 \times 10^7} = \frac{3 \times 10^{-1} \times 10^{5}}{4 \times 10^{-1} \times 10^7})

(\frac{3 x 10^4}{4 x 10^4})

(\frac{3}{4}) x 10^4-6 = 0.75 x 10^-2

= 7.5 x 10^-3