Toán $\frac{18}{5x +21}$ = $\frac{27}{34}$ Tìm x ( dùng tỉ lệ thức) 31/08/2021 By Samantha $\frac{18}{5x +21}$ = $\frac{27}{34}$ Tìm x ( dùng tỉ lệ thức)
$\frac{18}{5x+21}$ =$\frac{54}{15x+63}$ =$\frac{27}{34}$ =$\frac{54}{68}$ => $\frac{54}{15x+63}$=$\frac{54}{68}$ =>15x+63=68 =>15x=5 =>x=$\frac{1}{3}$ Trả lời
Đề: $\frac{18}{5x + 21}$ = $\frac{27}{34}$ Ta có: $\frac{18}{27}$ = $\frac{5x + 21}{34}$ => $\frac{2}{3}$ = $\frac{5x + 21}{34}$ => $\frac{68}{102}$ = $\frac{3(5x + 21)}{102}$ => 3(5x + 21) = 68 => 15x + 63 = 68 => 15x = 5 => x = $\frac{1}{3}$ Trả lời
$\frac{18}{5x+21}$ =$\frac{54}{15x+63}$ =$\frac{27}{34}$ =$\frac{54}{68}$
=> $\frac{54}{15x+63}$=$\frac{54}{68}$
=>15x+63=68
=>15x=5
=>x=$\frac{1}{3}$
Đề: $\frac{18}{5x + 21}$ = $\frac{27}{34}$
Ta có: $\frac{18}{27}$ = $\frac{5x + 21}{34}$
=> $\frac{2}{3}$ = $\frac{5x + 21}{34}$
=> $\frac{68}{102}$ = $\frac{3(5x + 21)}{102}$
=> 3(5x + 21) = 68
=> 15x + 63 = 68 => 15x = 5 => x = $\frac{1}{3}$