Math Question Help

Yodylann SG

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

FireIce SG

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)

Yodylann SG

Thank you very much i will be sure to post more once i have more issues

Yodylann SG

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)

FireIce SG

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

Yodylann SG

ah got it thanks a lot

FireIce SG

(16+14)(16-14)

= (30)(2)

= 60

Seowlah SG

O level typical question on this topic

without using a calculator, calculate 88888 - 88881 x 88895 ?