Объяснение:
m0*t0+m*t=(m0+m)*t1
m0*t0+k*m*t=(m0+k*m)*t2
к=3
t0=20
t1=30
t2=40
m*(t-t1)=m0(t1-t0)
k*m*(t-t2)=m0*(t2-t0)
m=m0(t1-t0)/(t-t1)
k*m=m0*(t2-t0)/(t-t2)
k*m=k*m0(t1-t0)/(t-t1)=m0*(t2-t0)/(t-t2)
k*m0(t1-t0)/(t-t1)=m0*(t2-t0)/(t-t2)
k*(t-t2)*(t1-t0)=(t2-t0)*(t-t1)
k*t*(t1-t0)-k*t2*(t1-t0)=(t2-t0)*t-(t2-t0)*t1
k*t*(t1-t0)-(t2-t0)*t=k*t2*(t1-t0)-(t2-t0)*t1
t*(k*(t1-t0)-(t2-t0))=k*t2*(t1-t0)-(t2-t0)*t1
t=(k*t2*(t1-t0)-(t2-t0)*t1) /(k*(t1-t0)-(t2-t0))
t=(3*40*(30-20)-(40-20)*30) /(3*(30-20)-(40-20))=60 - это ответ
