My age is the difference between twice my age in 4 years and twice my age 4 years ago how old am I?

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

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

Aline passes through the point (–7, 5) and has a slope of 1/2 which is another point that the line passes through?