Which relationship between x and y in the equation shows a proportional relationship?

a: y + 5 = x + 3

b: y = 5 (x + 3)

c: y= 5x + 3

d: y=3x

you guys are smarter than me,

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

100 points, hi, i’m not sure what to do here,the data doesn’t seem to be quadratic .? can anyone me, in advance

Find the length of the diagonal of the rectangle. round your answer to the nearest tenth. || | | 8 m | | | | 11 m