S=70t
S(2,4)=70×2,4=168
S(3,8)=70×3,8=266
4х+3у= 4*(-3/4)+3*(1/6)= (-3)+1/2= -2,5
4x-3y=4*(-3/4)-3*1/6= (-3) - 1/2=-3,5
X²-5x+5-x=0
x²-6x+5=0
D=36-20=16=4²
x1=(6+4)/2=5
x2=(6-4)/2=1
x²-9x-(x-9)=0
x²-9x-x+9=0
x²-10x+9=0
D=100-36=64=8²
x1=(10-8)/2=1
x2=(10+8)/2=9