Step: Finding whether the given equation is quadratic or not:
The standard form of a quadratic equation is ax2+bx+c=0, where a, b and c are all real numbers and a≠0.
Given equation is:
5x2−8x=−3(7−2x)
⇒5x2−8x=−21+6x
⇒5x2−8x−6x+21=0
⇒5x2−14x+21=0;
The given equation is of the form ax2+bx+c=0,
∴ Given equation is a quadratic equation.