Question

Решить уравнения
х +280=640
70*а=560
а*25=75

Answer 1

X + 280 =640
380x =640
X= 640- 380
X = 260

70 * a =560
80a=560
a= 560:80
a =70

a * 25= 75
a= 75 : 25 = 3