Question

va rog ajutatima la ex 5&6

Answer 1

5)
a)x\21=4\7⇒7x=21x4⇒7x=84⇒x=84\7⇒x=12
b)32\x=28\7⇒28x=32x7⇒28x=224⇒x=224\28⇒x=8
c)x+1\14=10\7⇒7(x+1)=14x10⇒7x+7=140⇒7x=140-7⇒7x=133⇒x=133\7⇒x=19
d)15\3=2x+1\27⇒3(2x+1)=15x27=6x+3=405⇒6x=405-3⇒6x=402⇒x=402\6⇒x=67

6)
a)2x+2\28=5\7⇒7(2x+2)=28x5⇒14x+14=140⇒14x=140-14⇒14x=126⇒x=126\14⇒x=9
b)3x+2\35=4\7⇒7(3x+2)=4x35=⇒21x+14=140⇒21x=140-14⇒21x=126⇒x=126\21⇒x=6

c)2x²-14\108=2\6⇒6(2x²-14)=108x2⇒12x²-84=216⇒12x²-84-216=0⇒12x²-300=0

d)51\x²+38=3\7⇒3(x²+38)=51x7⇒3x²+114=357⇒3x²+114-357=0⇒3x²-243=0

succes