## anonymous 4 years ago A laptop computer purchased for \$1400. After each year the resale value decreased by 35%. What will be the resale value after 4 years?

1. anonymous

1400(1-.35)^4

2. anonymous

Year 1 (35% of 1400= 490) 1400- 490= 910 Year 2 (35% of 910 = 318.5) 910- 318.5= 591.5 Year 3 (35% of 591.5= 207 * rounded to the nearest hundredth*) 591.5- 207= 384.5 Year 4 (35% of 384.5 = 134.6 *rounded to the nearest hundredth* ) 384.5 - 134.6= 249.9.

3. anonymous

@flapdragon why do such long calculation you will get same answer as mine unless you haven't made any mistake

4. anonymous

Just in case the person who asked the question needs to know how I got the answer. :)

5. anonymous

in this case a=1,b=k,c=k+1 so for $\Delta = k ^{2}-4\left( k +1 \right) =k ^{2}-4k -4$ now use quadratic formula on this to find k.$\div 2k=\left( 4\pm \sqrt{16-4\times -4} \right)\div2=\left( 4\pm \sqrt{32} \right)\div2=\left( 4\pm4\sqrt{2} \right)$$\div2=2\pm2$