Solve using the addition and mutiplication principles 7-10z>5

Question

Solve using the addition and multiplication principles 7-10z>5

Answer 1

7-10z>5,

7>5+10z,

7-5>10z,

2>10z,

1>5z is the same as 5z<1, z<⅕ is the solution.

CHECK

Let z=0 then 7-0>5 is true because 0<⅕.

Let z=⅖ then 7-4<5 because 3<5 and ⅖>⅕ which is contrary to z having to be less than ⅕.

When z=⅕, 7-10z=7-2=5 which is not greater than 5 so z cannot be ⅕.