Element X is a radioactive isotope such that every 14 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 80 grams, how much of the element would remain after 18 years, to the nearest whole number?

Follow these steps using the algebra tiles to solve the equation −5x + (−2) = −2x + 4. 1. add 5 positive x-tiles to both sides and create zero pairs. 2. add 4 negative unit tiles to both sides and create zero pairs. 3. divide the unit tiles evenly among the x-tiles. x =

Twenty points. suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet

Lola says these two expressions have the same value. expression a expression b which explains whether lola is correct?