In one grade of 150 students, the ratio of boys to girls is 2 : 3. How many boys are in that grade?

60 boys are in the grade.

Step-by-step explanation: Since there are 150 students, we can divide that number by the combined ratio, which in this case is 5. Dividing 150 by 5 would yield 30 students. We can use this information to multiply the given number of boys in the ratio by 30, which would produce 60.

irrational, cannot

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.