Question

Coroană 1+3+5+....+(2x-1) = 100 x=?plz help

Answer 1

$\displaystyle 1+3+5+...+(2x-1)=100 \\ \frac{(1+2x-1)\cdot x}{2}=100 \\ \frac{2x \cdot x}{2} =100 \\ \\ \frac{\not 2x^2}{\not 2} =100 \\ \\ x^2=100 \\ x= \sqrt{100} \\ \boxed{x=10}$