Bài thuyết trình chưa có tiêu đề

There is a proportional relationship that exists between the number of male students in relation to the overall student body. There are 120 students in the 7th grade, and 65 are male students. If there are 78 boys in 8th grade, how many students are in 8th grade?

Identify whether each pair of ratios forms a proportion or not. (Yes or No)

$\frac{5}{4}\ and\ \frac{15}{12}$

Solve the following proportion:

$\frac{3}{2}=\frac{9}{x-2}$  

The distance that an automobile travels varies directly as the time it travels. If the car travels 280 miles in 7 hours, how far will it travel in 12 hours?

Jenny has finished 12 of the 20 lessons in her piano book. Liam has finished the same percent of lessons from his piano book. His book contains 30 lessons. How many lessons has Liam finished?

Solve the equation. If the real solution is M and the extraneous solution is N, what is the value of $\frac{1}{2}MN$ ?

$\frac{x-1}{2x^2-9x-5}=\frac{x+3}{2x^2+5x+2}$