First find the interest rate of the sum of money doubles in 20 years 2p=p (1+rt) 2=1+rt. T=20 years 2=1+20r Solve for r to get the simple interest rate 2-1=20r 20r=1 R=1÷20 R=0.05
Now find how long will get triple at the same rate 3p=p (1+rt) 3=1+rt. R=0.05 3=1+0.05t Solve for t 3-1=0.05t 0.05t=2 T=2÷0.05 T=40 years. .....answer
B. The equation can become −2(4x − 1) = 12 by applying the addition property of equality because we have: <span>−2(4x − 1) − 7 = 5 / + 7 <=> -2(4x-1) = 12;</span>
