Round each addend to the nearest whole number and estimate the sum
19.43+11.5+3.08

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

Hardest math question of all time can you solve the equation. check for extraneous solutions.9∣9-8x∣ = 2x+3

Se tiene en una caja de canicas 10, 4 blancas y 6 negras ¿cual es la probabilidad que en 2 extracciones con reemplazo sean blancas? ¿cual es la probalidad que en 2 extracciones sin reemplazo sean negras?