Given: <span>mantle layer of earth begins about 70 kilometers underneath the surface </span><span>outer core begins about 2970 kilometers underneath the surface
Since we need to find the position of each layer </span><span>relative to the surface, the surface will serve as the point of origin or 0. Below the surface infers a negative value. So, Mantle layer is -70 km from the surface while outer core is -2970 km under the surface.
Comparing -70 and -2970, -70 has a greater value than -2970. The nearer the number is to the origin or 0, the higher its value.
Comparing the absolute greater value of -70 and -2970, -2970 has a greater absolute value. This is because absolute value is the positive value of the number. Absolute value of -70 is 70 while absolute value of -2970 is 2970. Thus, -2970 has a greater absolute value. </span>
Have the unknown amount = x so 3x : 9x you know how many kids meals were bought is equal to the ratio (3x = 12, so x=4) you already know how many X's for the adults (9) so just multiply (9x4= 36) lastly add since you need to find the total meals bought (36+12= 48)
