Iam a fraction equivalent to 2/5. my numerator is 21 less than my denominator. what fraction am i?

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x