#1**+5 **

$$\\x^ 2 +3x-8=80\\\\

x^ 2 +3x-88=0\\\\$$

now I need two numbers that multiply to -88

(forgetting about the minius sign it could be 8*11, 2*44, 1*88 or 4*22 )

Mmm one must be neg and one must be positive because they mult to a negative.

these numbers must also add to +3. that means the 'bigger' one is positive.

must be +11 and -8

(x+11)(x-8)=0

x+11=0 or x-8=0

x=-11 or x=8

Melody
Mar 31, 2015

#1**+5 **

Best Answer

$$\\x^ 2 +3x-8=80\\\\

x^ 2 +3x-88=0\\\\$$

now I need two numbers that multiply to -88

(forgetting about the minius sign it could be 8*11, 2*44, 1*88 or 4*22 )

Mmm one must be neg and one must be positive because they mult to a negative.

these numbers must also add to +3. that means the 'bigger' one is positive.

must be +11 and -8

(x+11)(x-8)=0

x+11=0 or x-8=0

x=-11 or x=8

Melody
Mar 31, 2015