Before we start, im doing quadratic equation stuff - year 10 - having trouble with this question
a rectangular painting is to have a total area (including frame) of 1200cm^2. The painting is 30m and 20cm wide, find the width of the frame. answer is 5cm
let x be the width of frame
(30+2x)(20+2x) = 1200
600+100x+4x^2 =1200
4x^2+100x-600=0
x^2+25x-150=0
(x-5)(x+30)=0
x=5 or -30 (rej as length cannot be -ve)
Thank you very much i will be sure to post more once i have more issues
A pool 6m by 3m is to have a path surronding it. If the total area of the pool and path is to be 31m^2. Find the width of the path correct to the nearest cm (which is . of a m) (answer is 63cm)
let the width of the path be y
(6+2y)(3+2y) =31
18+18y+4y^2= 31
4y^2+18y-13=0
y = 0.63314 or -5.13314 (rej as length cannot be -ve)
0.63314 m = 63cm
ah got it thanks a lot
(16+14)(16-14)
= (30)(2)
= 60
O level typical question on this topic
without using a calculator, calculate 88888 - 88881 x 88895 ?