Resolva os sistemas de equações a seguir pelo método da adição: a) 3x + y = 10
2x - 2y = 4

b) x + 2y = 9
3x + y = 7

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Seattle, washington is known for being rainy. one day last month, 8 inches of rain fell in 1 1/2 hours. what us the rate of the rainfall expressed in ft per plzzz write a proportion i will give you 100 points