SOLUTION: solve by substitution method: x + 3y = -8,4x - 3y = 23 solve by substitution: x - 2y = -3 and y = 2x - 3 find f(-2) given that f(s) = -x^2 - 4x + 23

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Question 173659: solve by substitution method: x + 3y = -8,4x - 3y = 23
solve by substitution: x - 2y = -3 and y = 2x - 3
find f(-2) given that f(s) = -x^2 - 4x + 23

Answer by jojo14344(1513)   (Show Source): You can put this solution on YOUR website!
solve by substitution method: EQN 1,
, EQN 2
In EQN 1 we get, , EQN 3, subst in EQN 2:


, divide both terms by
, subst in EQN 3


Check via EQn 1:


close enough
.
solve by substitution: , EQN 4 and , EQN 5
In EQN 4:
, EQN 6, subst in EQN 5:



----->
, subts in EQN 6


Check via EQN 5:


good
.
find f(-2) given that f(s) = -x^2 - 4x + 23


Thank you,
Jojo

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