52
The Quadratic Formula
Rearrange the following in the form "axe + bx + c = 0" and then solve by the quadratic formula. Give your answers to two decimal places.
a) x2 = 8 – 3x b) (x + 2)2– 3 =0 c) 3x(x – 1) = 5 d) 2x(x + 4) = 1
e) X2 = 4(x + 1) 1) (2x – 1)2= 5 g) 3x2 + 2x = 6 (x + 2)(x + 3) = 5
i) (x – 2)(2x – 1) = 3 j) 2x + 4 = 7 x k) (x 1)2= 1) 4x(x – 2) = –3
f() Pythagoras... remember him — you know, rt-,_.446,._ that bloke who didn't like angles.
The sides of a right-angled triangle are as shown. Use Pythagoras' theorem to form a quadratic equation in x and then solve it to find x.
2x cm
¦
(x + 3) cm
The area of a rectangle with length (x + 4.6) cm and width (x – 2.1) cm is 134.63 cm2. a) Form a quadratic equation and solve it to find x to two decimal places. b) What is the rectangle's perimeter to one decimal place?
4 (x + 4.6) cm —0
(x – 2.1) cm
SECTION THREE — ALGEBRA