Question

urgent va rog ajutor dau coroana urgent? ???

Answer 1

are sens doar pt dreptunghi in B
atunci BD este inalt coresp ipotenuzei AC
aplicam teorema inaltimii
 BD²=AD*DC
fie AD=x
8²=x(20-x)
64=20x-x²
x²-20x+64=0
x1,2 =(20+-√(400-256))/2=(20+-12)/2
x1=AD=16⇒DC=4⇒(pitagora in ΔdrADB), AB=8√5⇒(pitagoraΔABC,BC=4√5


x2=AD'=4⇒DC=16⇒(Pitagora in Δdr.BDC,  BC=8√5⇒(pitagora inΔABC, AB=4Δ5
solutiile sunt simetrice

dac n-ai invata s ec de grad 2
x²-20x+64=0
x²-16x-4x+64=0
x(x-16)-4(x-16)=0
(x-16)(x-4)=0
x1=4
x2=16