Answer:
y^2 +10y+21
Step-by-step explanation:
(y+7)•(y+3)
FOIL
first: y*y = y^2
outer: 3*y = 3y
inner 7*y = 7y
last 7*3 =21
Add together
y^2 +3y +7y +21
Combine like terms
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[tex](y+7).(y+3)\\\\y(y+3)+7(y+3)\\\\y^2+3y+7y+21\\\\\pmb{\red{\boxed{y^2+10y+21}}}[/tex]
