4X+20=25
4X=25-20
4X=5
X=5/4
X=1 1/4
7)Moskvish is old car. Zhiguli is older than moskvish. Zaporozhets is the oldest.
5)Bentley is modern car. Toyota is more modern than Bentley. Hyundai is the most modern car.
15(53-8x)=75
795-75=120x
720=120x
X=6
Y=7/5 или
у=1 целая 2/5 и у= 1,4