Could anybody help me with solving this equation?

[Albert Chan]

Try replacing approximate number 0.01 as 1/100

Cas> m1 := [[-p1*t1+1, t1], [-p1^2*t1, p1*t1+1]]
Cas> solve([-m1(1,1)/-m1(2,1)=50, -m1(2,1)=1/100], [p1,t1])

{[1/150, 225]}

Or, do this symbolically, then replace with approx. numbers

Cas> solve([-m1(1,1)/-m1(2,1)=a, -m1(2,1)=b], [p1,t1]) (a=50, b=0.01)

{[6.66666666667e−3, 225.]}