Question

How do you solve `(x-3)(x+7)=0`?

Answer 1

`x=3color(white)("XX")orcolor(white)("XX")x=-7`

Explanation:

If `(a xx b) = 0` then either `(a=0)` or `(b=0)`

Based on this observation, we see that if `(x-3)(x+7)=0` then
either
`color(white)("XXX")x-3=0color(white)("XX")rarrcolor(white)("XX")x=3`
or
`color(white)("XXX")x+7=0color(white)("XX")rarrcolor(white)("XX")x=-7`

Answer 2

`x={-7,3}`

Explanation:

`(x-3)(x+7)=0`

`if (x-3)=0" " rArr" "x=3`

`if(x+7)=0" "rArr" "x=-7`

`x={-7,3}`