The sale price of a diving board is $213. What was the original price if it was 25% off?

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°

The ratio of the perimeters of two similar triangles is 4: 3. what are the areas of these triangles if the sum of their areas is 130cm2?