1 square kilometre equals to 100000000000 square centimetres Express it in scientific notation

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

What is the value of the expression below? 148+(-6)| + |– 35= 7|