Question

Ajutoooor, dau coroana si puncte!!!!! E urgent!! Sper sa intelegeti

Answer 1

a) a/8=5/b=>ab=8×5
                     ab=40

ab+10=40+10
ab+10=50

2ab-30=2×40-30
2ab-30=80-30
2ab-30=50

b) x/10=y/7=>x=10y/7 (1)
   14x+5y=350 (2)
Înlocuim (1) în (2)=> 14×10y/7+5y=350
                                  2×10y+5y=350
                                  20y+5y=350
                                  25y=350
                                  y=350:25=>y=14
    x=10y/7=10×14/7
               x=20

c) 2a+3b/3a+2b=15/11=>15(3a+2b)=11(2a+3b)
                                        45a+30b=22a+33b
                                        45a-22a=33b-30b
                                        23a=3b=>a/b=3/23