How do i solve the system of equations using substitution?

Erin bought christmas cards for $2 each to send to her family and friends. which variable is the dependent variable?

Acertain group of women has a 0.640.64% rate of red/green color blindness. if a woman is randomly selected, what is the probability that she does not have red/green color blindness? what is the probability that the woman selected does not have red/green color blindness? nothing (type an integer or a decimal. do not round.)

Which is the standard form of the equation of the parabola that has a vertex of (-4,-3) and a directrix of x = 2? (x+3)2 = 24(y+4) (y+3)² = 24(x-4) (y+3)² = -24(x+4) (x+3)2 = -24(y+4)