All I did was think, what can I multiply 3x and 4x by so when I add those products together, I get 28? If I do 3x * 4 = 12, and 4x * 4 = 16. 16+12=28! In any “FOILED” form, the last values when multiplied are the “c” value in the standard quadratic equation (ax^2+bx+c). So I concluded that a^2 = b. If a was 4 from what I did, then 4^2 = 16 which means b is 16!

## Comments (2)

take the oi out of the Foil

F=3x*4x

O and I is

a(4x) +a( 3x)= 28x

L is a^2

a( 3+4)=28 remove the x because we are just intertested in the number

a(7) = 28 or (4*3) + (4*4)

a=4

L = a^2 or 16 b= a^2 or 16

All I did was think, what can I multiply 3x and 4x by so when I add those products together, I get 28? If I do 3x * 4 = 12, and 4x * 4 = 16. 16+12=28! In any “FOILED” form, the last values when multiplied are the “c” value in the standard quadratic equation (ax^2+bx+c). So I concluded that a^2 = b. If a was 4 from what I did, then 4^2 = 16 which means b is 16!

Final Answer: 16