a)5x-49=51
⇔5x=51+49
⇔5x=100
⇔x=100÷5
⇔x=20
vậy x=20
b)6-3(x+1)=14
⇔3(x+1)=6-14
⇔3(x+1)=-8
⇔x+1=-8÷3
⇔x+1=-$\frac{8}{3}$
⇔x=-$\frac{8}{3}$ -1
⇔x=-$\frac{11}{3}$
vậy....
c)2$(x-1)^{2}$ +4=36
⇔2$(x-1)^{2}$=36-4
⇔2$(x-1)^{2}$=32
⇔$(x-1)^{2}$=32÷2
⇔$(x-1)^{2}$=16
⇔$(x-1)^{2}$=$4^{2}$
⇔x-1=4
⇔x=4+1
⇔x=5
vậy....
d)║x-5║-9=35
⇔║x-5║=35+9
⇔║x-5║=44
⇒\(\left[ \begin{array}{l}x-5=-44\\x-5=44\end{array} \right.\) ⇒\(\left[ \begin{array}{l}x=-39\\x=49\end{array} \right.\)
vậy x=-39 hoặc x=49
CÂU f MK CHX NGHĨ RA ,BN THÔNG CẢM NHÉ
CHÚC BN HK TỐT
