Question

помогите!!!решить 2 уравнения: (80-х)*5+20=370 и (640:у)*9-27=45

Answer 1

(80-х)*5+20=370

80*5-х*5+20=370

400-5х+20=370

420-5х=370

5х=420-370

5х=50

х=50/5

х=10

 

(640:у)*9-27=45

(640:у)*9=45+27

(640:у)*9=72

640:у=72:9

640:у=8

у=640:8

у=80