Can somebody help me with this?

How do you find principle and simple interest

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90