D. 10 is your answer. In order to solve a proportion, you cross multiply. In this case it will be 40=4x Solve for x is 10. Therefore D is your answer. Please give 5 star if it helped you. :)
X² + y = 4 and -y³ = 1x -5 are not linear equation because they contain a variable with a exponents. These types of equation are called quadratic equations.
