If x, y, z and L are proportional
quantities, prove that: 3x+ 5z/ 7x+z = 3y+5L/7x+ L

Zoe placed colored blocks on a scale in science class. each block weighed 0.8 ounces. the total weight of all the colored blocks was 12.8 ounces. how many blocks did zoe place on the scale? write and solve an equation to find the answer.

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Construct the graph that models the given situation