What is the solution to this equation 5x-x+12+2x-7=10

What is the approximate circumference of the circle shown below?

What is true about the dilation? it is a reduction with a scale factor between 0 and 1. it is a reduction with a scale factor greater than 1. it is an enlargement with a scale factor between 0 and 1. it is an enlargement with a scale factor greater than 1.

Solve the equation for b: a= (1/2)(b)(h)