Question

Which equation can be solved by using this system of equations?

Answer 1

In order to solve the system of equations given in the picture, we can set them both equal to each other. Since the left hand side of both equations is same i.e. equal to y, so we can say the left hand side must also be equal.

So equating the left hand side of both equations and then solving the equality will give us the solution to both equations.

Therefore, the correct option is B

Answer 2

Answer: the second option 3x³ - 7x² + 5 = 7x⁴ + 2x.

Justification:

Since you have two clearly separated members, you can build a system of equations using each side:

Left side: y = 3x³ - 7x² + 5
Righ side: y = 7x⁴ + 2x.

What advantageous could represent that?

You might, for example, draw the graphs of both functions, y =  3x³ - 7x² + 5 and y = x⁴ + 2x, in the same plane, and the intersection points will be the solutions of the system and, hence, of the original equation.