Zgjidhja e ushtrimit 12 të mësimit 1.2Z në librin Matematika 10 - 11: Pjesa II nga shtëpia botuese Botime Pegi me autorë Steve Fearnley, June Haighton, Steve Lomax, Peter Mullarkey, James Nicholson dhe Matt Nixon.
Pyetja
Tregoni se 2×4x+322x+4=8\dfrac{2 \times 4^{x+3}}{2^{2x+4}}=822x+42×4x+3=8.
Zgjidhja
2×4x+322x+4=8⇒2×(22)x+322x+4=23⇒2×22x+622x+4=23⇒21+2x+622x+4=23⇒22x+722x+4=23⇒22x+7−(2x+4)=23⇒22x+7−2x−4=23⇒23=23\begin{aligned} \dfrac{2 \times 4^{x+3}}{2^{2x+4}}=8 &\rArr \dfrac{2 \times (2^2)^{x+3}}{2^{2x+4}} = 2^3\\ &\rArr \dfrac{2 \times 2^{2x+6}}{2^{2x+4}} = 2^3 \\ &\rArr \dfrac{2^{1 + 2x + 6}}{2^{2x+4}} = 2^3 \\ &\rArr \dfrac{2^{2x + 7}}{2^{2x+4}} = 2^3 \\ &\rArr 2^{2x + 7 - (2x + 4)} = 2^3 \\ &\rArr 2^{2x + 7 - 2x - 4} = 2^3 \\ &\rArr 2^3 = 2^3 \\ \end{aligned}22x+42×4x+3=8⇒22x+42×(22)x+3=23⇒22x+42×22x+6=23⇒22x+421+2x+6=23⇒22x+422x+7=23⇒22x+7−(2x+4)=23⇒22x+7−2x−4=23⇒23=23
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