Question

How do you find a=0.4b-1.2c given b=<6,3> and c=<-4,8>?

Answer 1

`a= < 7.2, -8.4>`

Explanation:

If
`color(white)("XXX")color(blue)(b=<6,3>` and
`color(white)("XXX")color(red)(c=<-4,8>`

then
`color(white)("XXX")color(green)a =0.4color(blue)(b)-1.2color(red)(c)`

`color(white)("XXX")rarr color(green)(a = 0.4color(blue)(<6,3>)-1.2color(red)(<-4,8>))`

`color(white)("XXX")rarr color(green)(a= color(magenta)(<0.4 * 6, 0.4 * 3>)-color(orange)(<1.2 * (-4), 1.2 * 8>))`

`color(white)("XXX")rarr color(green)(a = color(magenta)(<2.4, 1.2>) - color(orange)(<-4.8,9.6>)`

`color(white)("XXX")rarr color(green)(a = < color(magenta)(2.4)+color(orange)(4.8), color(magenta)(1.2)-color(orange)(9.6)>`

`color(white)("XXX")rarrcolor(green)(a=< 7.2, -8.4 >)`