How many solutions does the following system have? 7x+5y=4; -21x-15y=-12

a)infinitely many solutions
b)one solution
c)two solutions
d)no solutions

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.