Finance Unit

1.5 Order in Calculations/Evaluating Formulas

Simplify each expression. Show each step one at a time.

  1. \(7-24 \div 3 \times 4+6\)

    \(7-8 \times 4+6\)

    \(7-32+6\)

    \(-25+6\)

    \(-19\)

  2. \(20(3+7)\)

    \(20(10)\)

    \(200\)

  3. \(12+4^{2}\)

    \(12+16\)

    \(28\)

  4. \(6\left(5-3\right)^{2}\)

    \(6\left(2\right)^2\)

    \(6(4)\)

    \(24\)

  5. \(200 \times(1+0.04 / 12)^{5 \times 12}\)

    \(200 \cdot\left(1+\frac{1}{300}\right)^{60}\)

    \(200 \cdot\left(\frac{301}{300}\right)^{60}\)

    \(200 \cdot 1.2210\)

    \(244.20\)

  6. \(50 \times \frac{\left[(1+0.05 / 12)^{12 \times 10}-1\right]}{(0.05 / 12)}\)

    \(7764.11\)

  7. \(\frac{180000 \times(0.065 / 12)}{\left[1-(1+0.065 / 12)^{(-12 \times 15)}\right]}\)

    \(1567.99\)

  8. \(\pi(8)^{2}\)

    \(64 \pi\)

    \(201.0619\)

  9. \(\frac{4}{3} \pi(7.5)^3\)

    \(\frac{4}{3} \pi \left(421.875\right)\)

    \(562.5 \pi\)

    \(1767.1459\)

  10. \(\frac{1}{2} \times 15(3.2+10.8)\)

    \(\frac{1}{2} \times 15(14)\)

    \(7.5 \cdot 14\)

    \(105\)

  11. Evaluate \(I=\operatorname{Prt} \text { when } P=2000, r=0.045, \text { and } t=\frac{11}{12}\)

    \(I=2000 \cdot 0.045 \cdot \frac{11}{12}\)

    \(I=\$82.50\)

  12. Find the simple interest earned on $3000 at an annual interest rate of 3.75% for 4 years. Use the simple interest formula \(I=Prt\) where \(P\) is the principle invested, \(r\) is the annual interest rate in decimal form, and \(t\) is the number of years.

    \(I=3000 \cdot 0.0375 \cdot 4\)

    \(I=\$450\)

  13. Evaluate \(A=P\left(1+\frac{r}{n}\right)^{n t} \text { when } P=2000, r=0.045, n=12, \text { and } t=\frac{11}{12}\)

    \(A=2000\left(1+\frac{.045}{12}\right)^{12 \cdot \frac{11}{12}}\)

    \(\$2084.06\)

  14. Find the accumulated amount when $3000 is invested for 4 years at a 3.75% interest rate compounded monthly. Use the compound interest formula \(A=P\left(1+\frac{r}{n}\right)^{n t}\) where \(P\) is the principle invested, \(r\) is the annual interest rate in decimal form, \(t\) is the number of years, and \(n\) is the number of compounding periods in a year.

    \(A=3000\left(1+\frac{.0375}{12}\right)^{12 \cdot 4}\)

    \(A=\$3484.69\)

  15. Evaluate \(A=P M T \times \frac{\left[\left(1+\frac{R}{n}\right)^{n t}-1\right]}{\left(\frac{R}{n}\right)} \text { when } P M T=\$ 250, R=0.02, t=20, \text { and } n=12\)

    \(A=\frac{250\left[\left(1+{\displaystyle\frac{.02}{12}}\right)^{12\ast20}-1\right]}{\left({\displaystyle\frac{.02}{12}}\right)}\)

    \(A=\$73699.21\)

  16. Find the accumulated amount when $1000 is invested every month for 3.5 years at a 3% interest rate compounded monthly. Use the savings plan formula \(A=P M T \times \frac{\left[\left(1+\frac{R}{n}\right)^{n t}-1\right]}{\left(\frac{R}{n}\right)}\) where \(PMT\) is the monthly payment, \(R\) is the annual percentage rate, \(t\) is the number of years, and \(n\) is the number of compounding periods per year.

    \(A=\frac{1000\left[\left(1+{\displaystyle\frac{.03}{12}}\right)^{12\ast3.5}-1\right]}{\left({\displaystyle\frac{.03}{12}}\right)}\)

    \(A=\$44226.03\)

  17. Evaluate \(a^{2}+b^{2}=c^{2} \text { when } a=5 \text { and } b=12\)

    \(5^{2}+12^{2}=c^{2}\)

    \(c^{2}=25+144\)

    \(c^{2}=169\)

    \(\sqrt{c^2}=\sqrt{169}\)

    \(c=13\)

  18. Find the length of the hypotenuse of a right triangle when the legs are 14 cm and 48 cm. Use the Pythagorean Theorem \(a^{2}+b^{2}=c^{2}\).

    \(14^{2}+48^{2}=c^{2}\)

    \(c^{2}=2500\)

    \(c=50\) cm

  19. Evaluate \(x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}\) when \(a = 3, b = -6,\) and \(c = 2\). Find both solutions to the nearest hundredth.

    \(x=\frac{6 \pm \sqrt{(-6)^{2}-4(3)(2)}}{2 \cdot 3}\)

    \(x=\frac{6 \pm \sqrt{12}}{6}\)

    \(x \approx 1.58,0.42\)

  20. Find the solutions to the equation \(-2 x^{2}+12 x+10=0\). The equation is in standard form \(a x^{2}+b x+c=0\). Use the quadratic formula \(x=\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}\) to solve for x. Find both solutions to the nearest hundredth.

    \(x=\frac{-12 \pm \sqrt{12^{2}-4(-2)(10)}}{2 \cdot-2}\)

    \(x=\frac{-12 \pm \sqrt{224}}{-4}\)

    \(x \approx-0.74,6.74\)