Someone please help out my grads are bad I already posed the question please help out

What are the soultion(s) to the quadratic equation 40- x^2=0

I’m really confused and need to learn this

Urgent? will give brainliest given that the blue triangle is a right triangle, which expression correctly gives the area of the red square? a) a2 + b2 b) a2 - b2 c) a2 - c2 d) c2 - a2