1995 - WAEC Mathematics Past Questions and Answers - page 2
Solve the inequality: \(\frac{1}{3}(2x - 1) < 5\)
\(\frac{1}{3}(2x - 1) < 5\)
\(2x - 1 < 15\)
\(2x < 16\)
\(x < 8\)
What is the smaller value of x for which x\(^2\) - 3x + 2= 0?
x\(^2\) - 3x + 2 = 0
x\(^2\) - 2x - x + 2 = 0
x(x - 2) - 1(x - 2) = 0
(x - 2)(x - 1) = 0
x = 1 or 2. The smaller value of x = 1.
Factorize the expression x(a - c) + y(c - a)
x(a - c) + y(c - a)
= x(a - c) - y(a - c)
= (x - y)(a - c)
If \(y \propto \frac{1}{x^2}\) and x = 3 when y = 4, find y when x = 2.
\(y \propto \frac{1}{x^2}\)
\(y = \frac{k}{x^2}\)
\(4 = \frac{k}{3^2}\)
\(k = 4 \times 3^2 = 36\)
\(y = \frac{36}{x^2}\)
When x = 2,
\(y = \frac{36}{2^2} = 9\)
Solve the equation 3x\(^2\) + 25x -18 = 0
3x\(^2\) + 25x - 18 = 0
3x\(^2\) + 27x - 2x - 18 = 0
3x(x + 9) - 2(x + 9) = 0
(3x - 2)(x + 9) = 0
x = \(\frac{2}{3}\) or x = -9.
Solve the equation (x +2)(x - 7) = 0
(x + 2)(x - 7) = 0
x + 2 = 0 \(\implies\) x = -2
x - 7 = 0 \(\implies\) x = 7
x = -2 or 7
Solve the following simultaneous equations: x+ y = 3/2; x - y = 5/2 and use your result to find the value of 2y + x
x + y = \(\frac{3}{2}\) ... (i)
x - y = \(\frac{5}{2}\) ... (ii)
(i) - (ii):
2y = \(\frac{-2}{2}\) = -1
y = \(-\frac{1}{2}\)
x + y = \(\frac{3}{2}\)
x - \(\frac{1}{2}\) = \(\frac{3}{2}\)
x = \(\frac{3}{2} + \frac{1}{2}\)
= \(\frac{4}{2}\)
x = 2
\(\therefore\) 2y + x = 2(\(-\frac{1}{2}\)) + 2
= -1 + 2 = 1.
Use the graph of y = 3x\(^2\) + x - 7 above to answer the question
What is the minimum value of y?
Use the graph of y = 3x\(^2\) + x - 7 above to answer the question
Find the roots of the equation y=3x\(^2\) + x - 7
In the diagram above. |AB| = 12cm, |AE| = 8cm, |DCl = 9cm and AB||DC. Calculate |EC|
|AB| = 12 cm; |DC| = 9 cm; |AE| = 8 cm.
\(\Delta\) ABE and \(\Delta\) EDC are similar triangles. Hence,
\(\frac{|AB|}{|DC|} = \frac{|AE|}{|EC|}\)
\(\frac{12}{9} = \frac{8}{|EC|}\)
\(\therefore |EC| = \frac{9 \times 8}{12}\)
= 6 cm