Translate the following into an inequality: What number plus four is at most 6?

k = 4 < 6
k + 4 ≤ 6
k + 4 > 6
k + 4 ≥ 6

Aquantity with an initial value of 3900 decays exponentially at a rate of 35% every hour. what is the value of the quantity after 0.5 days, to the nearest hundredth?

Given that abcd is a rhombus, what is the value of x?

The areas of two similar triangles are 72dm2 and 50dm2. the sum of their perimeters is 226dm. what is the perimeter of each of these triangles?