Question

Va rog mult 2,3,4 urgentttt!!!!!!​

Answer 1

Răspuns:

Explicație pas cu pas:

2.

4a=6b=9c        4a=6b  ⇔a=6b/4=3b/2  a=3b/2

6b=9c  ⇔c=6b/9=2b/3   c=2b/3

a+2b+3c=132

3b/2+2b+3·2b/3=132  ⇔3b/2+2b+2b=132  ⇔3b/2+4b=132  ⇔(3b+8b)/2=132  ⇔11b=264  ⇔b=264/11=24    b=24

a=3b/2=3·24/2=3·12=36    a=36

c=2b/3=2·24/3=2·8=16   c=16

3. x/5=y/7=k  

x=5·k     y=7·k

(3x+4y)/(5y-2x)=(3·5·k+4·7·k)/(5·7·k-2·5·k)=(15·k+28·k)/(35·k-10·k)= 43·k/25·k=43/25

4.

(1+2+3+...+50)/(3+6+9+...+150)=x/15  ⇔(1+2+3+...+50)/3·(1+2+3+...+50)=x/15  ⇔1/3=x/15  ⇔x=15/3=5   x=5