It is known that a + 2b + c = 4 for a, b,c€ R . Find the maximum value of ab + bc + ca .​

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

Sheila wants to bake six muffins but the recipe is for 12 muffins . this means you only need half of the ingredients listed how much of the of each ingredient does she need? one cup and banana chips ,7 tablespoons oil , two eggs, 3/4 cups flour 1/4 cup walnuts show all you work and justify your answer using a baby toulmin.

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"