The fourth one I think hope it helps
Let
x-------------> <span>the length of a rectangle
y-------------> the </span>width of a rectangle
we know that
x+y=130-----------> equation 1
and
x=1.6y--------------> equation 2
<span>I substitute 2 in 1
(1.6y)+y=130-------------> 2.6y=130------------> y=130/2.6------> y=50 ft
x=1.6y--------> x=1.6*50---------> x=80 ft
the answer is
</span>the length is 80 ft
the width is 50ft
Answer:
Suppose N is the size of a population of radioactive atoms at a given time t, and dN is the amount by which the population decreases in time dt; then the rate of change is given by the equation dN/dt = −λN, where λ is the decay constant.
