Question

tìm x biết: (5x+1)^2-(5x+3)(5x-3)=30

Answer 1

\(\left(5x+1\right)^2-\left(5x+3\right)\left(5x-3\right)=30\)

\(25x^2+10x+1-\left(25x^2-9\right)=30\)

\(25x^2+10x+1-25x^2+9=30\)

\(10x+10=30\)

\(10x=20\)

\(x=2\)

Answer 2

T_T tôi chưa hc lp 8

Answer 3

(5x+1)²-(5x+3)(5x-3)=30

=>25x²+10x+1-25x²+9=30

=>(25x²-25x²)+10x+1+9=30

=>10x+10=30

=>10x=20

=>x=2

Answer 4

​\(10^2=bao\)