Find for x to four significant digits. 7^x=13

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Hassan bought a package of tofu. the temperature of the tofu was 14° celsius when hassan put the package into the freezer. he left the tofu in the freezer until it reached –19° celsius. which expressions explain how to find the change in temperature, in degrees celsius, of the package of tofu? select three that apply.

What is the slope of the line that has an equation of y equals x -3