1. =2.7-1=1.7
2. =-3.6+y+y-2.6=-6.2+2y=2(-3.1+y)
3.=14.5x+2.2c
4. =-6a+12-5a=-11a-12
5. x=-24/-4
x=6
6. 2y+3y=19+4
5y=23
y=23/5=4.6
423 175 315 287
х х х х
80 400 200 500
25840 70000 63000 143500
X²+3x=18
x²+3x-18=0
D=3²-4*(-18)=81
x1=(-3-√81)/2=-6
x2=(-3+√81)/2=3