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Element X is a radioactive isotope such that every 90 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 30 grams, how much of the element would remain after 12 years, to the nearest whole number

Asap 25 pts brainliest to right best/answer

Pleting the square f the given find the x-intercepts of the parabola with vertex (-5,13) and y-intercept (0, 12). write your answer in this form: (14,.99). if necessary, round to the nearest hundredth. *- h enter the correct answer, de verter, and ametry 00000 done doo

Last year, laura had $30,000 to invest. she invested some of it in an account that paid 7% simple interest per year, and she invested the rest in an account that paid 8% simple interest per year. after one year, she received a total of $2230 in interest. how much did she invest in each account?