Given A = P + PRT, Solve for T

C. T = (A - P) / (PR)

Step-by-step explanation:

A = P + PRT

A - P = PRT

(A - P) / (PR) = T

Alvin 46, Elga 23

Step-by-step explanation:

So you set up two equations:

Before anything lets assume

age of Elga= E

age of Alvin= A

Then,

A= 2E (Alvin's age is 2x Elga's age) (EQ 1)

A+E=72 (Sum of Alvin's and Elga's age) (EQ 2)

Plug the value of A from eq1 to eq2.

A+E=72

2E+E=72 (we plugged here the value of A from eq1)

3E=72

E= 26 (Elga's Age)

Now solve for Alvin's age by plugging E in either equation:

A+E=72

A+26=72

A= 46yr (Alvin's Age)

or Plug in eq 1

A=2E

A= 2x23= 46yr (Alvin's Age)