9x+1+3x+2=18   решите пожалуйста  

9х+3х=18-1-2; 12х=15; х=15/12; х=1,25.

Solve for x: 9 x+3 x+1+2 = 18 Grouping like terms, 9 x+3 x+1+2 = (9 x+3 x)+(1+2): (9 x+3 x)+(1+2) = 18 9 x+3 x = 12 x: 12 x+(1+2) = 18 1+2 = 3: 12 x+3 = 18 Subtract 3 from both sides: 12 x+(3-3) = 18-3 3-3 = 0: 12 x = 18-3 18-3 = 15: 12 x = 15 Divide both sides of 12 x = 15 by 12: (12 x)/12 = 15/12 12/12 = 1: x = 15/12 The gcd of 15 and 12 is 3, so 15/12 = (3×5)/(3×4) = 3/3×5/4 = 5/4: Answer: | | x = 5/4. Удачи!