Question

I need help with an area math question

Answer 1

Explanation:

Area of outer triangle =
`(4x*(4x+3))/(2)= 2x*(4x +3)`

= 2x*4x + 2x*3

= 8x² + 6x

Area of inner triangle=
`(2x*(2x+5))/(2)=x*(2x+5)=x*2x+x*5=2x^(2) + 5x`

Area of aluminium = area of outer triangle - area of inner triangle

= 8x² + 6x + 2x² + 5x

= 10x² + 11x

Area of 20 aluminum borders = 20*(10x² + 11x) = 200x² + 220x

b) x = 25 cm

Area of 20 aluminum borders = 200*25² + 220*25

= 200 * 625 + 220*25

= 125000 + 5500

= 130500 cm²

c) Area of inner triangle (Glass) = 5500 cm²

Cost of aluminium = 130500 * 0.06 = $ 7830

Cost of glass = 5500 * 0.03 = $ 165

Cost of making 20 windows = 7830 + 165 = $ 7995