lm giúp mik với mik lười quá giải chi tiết giúp mik nha :3
\(a.\left(x-\dfrac{1}{2}\right)\times\dfrac{5}{3}=\dfrac{7}{4}-\dfrac{1}{2}\\ \left(x-\dfrac{1}{2}\right)\times\dfrac{5}{3}=\dfrac{5}{4}\\ x-\dfrac{1}{2}=\dfrac{5}{4}:\dfrac{5}{3}\\ x-\dfrac{1}{2}=\dfrac{3}{4}\\ x=\dfrac{3}{4}+\dfrac{1}{2}\\ x=\dfrac{5}{4}\\ b.2448:24=119-\left(x-6\right)\\ 102=119-\left(x-6\right)\\ x-6=119-102\\ x-6=17\\ x=17+6\\ x=23\\ c.\dfrac{1}{2}\times x+\dfrac{5}{3}\times x-x=3\\ x\times\left(\dfrac{1}{2}+\dfrac{5}{3}-1\right)=3\\ x\times\dfrac{7}{6}=3\\ x=3:\dfrac{7}{6}\\ x=\dfrac{18}{7}\\ d.15\times x-11\times x+x+4=25\\ x\times\left(15-11+1\right)=25-4\\ x\times5=21\\ x=\dfrac{21}{5}\)
\(e.\left(x+5\right)+\left(x+10\right)+\left(x+15\right)+...+\left(x+100\right)=1130\\ x+5+x+10+x+15+...+x+100=1130\\ \left(x+x+x+...+x\right)+\left(5+10+15+...+100\right)=1130\)
Số lượng số hạng là: (100 - 5) : 5 + 1 = 20 (số hạng)
Tổng: (100 + 5) x 20 : 2 = 1050
\(20\times x+1050=1130\\ 20\times x=1130-1050\\ 20\times x=80\\ x=80:20\\ x=4\)
