Question from my math test

Which statement is always true? a negative exponent cannot be part of an expression's numerator. a negative base raised to the power of 2 has a negative value. a negative base raised to the power of 2 has a positive value. any number to the first power is zero.

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Answer! if you don’t mind, can you explain