we are given
[tex]p=900-4t^2[/tex]
where
price p( in dollars) of a new smartphone
t is the number of months since January
now, we can solve for t
step-1:
Add both sides by 4t^2
[tex]p+4t^2=900-4t^2+4t^2[/tex]
[tex]p+4t^2=900[/tex]
step-2:
Subtract both sides by p
[tex]p+4t^2-p=900-p[/tex]
[tex]4t^2=900-p[/tex]
step-3:
divide both sides by 4
[tex]\frac{4t^2}{4} =\frac{900-p}{4}[/tex]
[tex]t^2=\frac{900-p}{4}[/tex]
[tex]t^2=225-0.25p[/tex]
step-4:
Take sqrt both sides
[tex]\sqrt{t^2} =\sqrt{225-0.25p}[/tex]
[tex]t=\sqrt{225-0.25p}[/tex]
so, we get
[tex]t=\sqrt{225-0.25p}[/tex]..............Answer
