X+5y=20 select the ordered pair that is a solution to the equation

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years

Which equation shows the variable terms isolated on one side and the constant terms isolated on the other side for the equation -1/2x+3=4-1/4x? a. -1/4x=1 b. -3/4x=1 c. 7=1/4x d. 7=3/4x

Which of the following represents the length of a diagonal of this trapezoid?