Question

tìm x,y,z biết:

x/4=y/5=z/7 và x+y-z= 66

Answer 1

Áp dụng t/c dãy tỉ số = nhau:

\(\frac{x}{4}=\frac{y}{5}=\frac{z}{7}=\frac{x+y-z}{4+5-7}=\frac{66}{2}=33\)

=> \(\frac{x}{4}=33\Rightarrow x=33.4=132\)

=>\(\frac{y}{5}=33\Rightarrow y=33.5=165\)

=>\(\frac{z}{7}=33\Rightarrow z=33.7=231\)

Vậy ...

Answer 2

Theo de bai ta co :

 \(\frac{x}{4}=\frac{y}{5}=\frac{z}{7}\) va x+y-z=66

Ap dung tinh chat day ti so bang nhau ta co : 

\(\frac{x}{4}=\frac{y}{5}=\frac{z}{7}=\frac{x+y-z}{4+5-7}=\frac{66}{2}=33\)

Suy ra : \(\frac{x}{4}=33\Rightarrow x=33.4=132\)

\(\frac{y}{5}=33\Rightarrow y=33.5=165\)

\(\frac{z}{7}=33\Rightarrow z=33.7=231\)