Number and Algebra

Pregunta	Respuesta
See a bracket – deal with it first!! 5(x + 2) = 15	5(x + 2) = 15 5x + 10 = 15 5x = 5 x = 1
To simplify surds like √50, you can split a surd into its factors When splitting, look for square numbers	√50 = √25 x √2 = 5√2 √98 = √49 x √2 = 7√2 √50 + √98 = 5√2 + 7√2 = 12√2
To find a % increase, you must do % increase = increase/original x 100 e.g. To increase from 7 to 12	% increase = 5/ 7 x 100 = 71%
To find equation of a straight line use y = mx + c	m = gradient c = y intercept
To increase by 5%, multiply by ?	1.05
To decrease by 17% multiply by ?	0.83
If a surd is on the bottom of a fraction, get rid of it!! If a surd is on the bottom such as √2, then multiply top and bottom by √2	22 / √2 = (22 x √2) / (√2 * √2) =22 * √2 / 2 = 11 * √2
If given that after a 22% decrease something costs £5 then ...	we know 78%=£5 then we find 1%= 6.41p and then 100% to get original price = £6.41

Resumen del Recurso

	Creado por Rick Wear hace más de 7 años