Respuesta :

Ozgr
[tex](y-3)(y+4)= 30[/tex] then you have [tex]y^2+4y-3y-12=30[/tex] ⇔ [tex]y^2+y-42=0 [/tex] ⇔ [tex](y+7)(y-6)=0[/tex]
apologiabiology
so first you expand
use foil or whatever
y²-3y+4y-12=30
y²+y-12=30
minus 30 from both sides
y²+1y-42=0
factor
what 2 numbers multiply to -42 and add to 1?
-6 andn 7
(y-6)(y+7)=0
set each to zero

y-6=0
y=6

y+7=0
y=-7

y=-7 or 6

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