Solve E(x)=7*1/20+8*1/4+9*2/5+10*3/10=

$$E ( x ) = 7 \times \frac { 1 } { 20 } + 8 \times \frac { 1 } { 4 } + 9 \times \frac { 2 } { 5 } + 10 \times \frac { 3 } { 10 } =$$

Evaluate

$$\frac{179}{20}=8.95$$

Solution Steps

Multiply 7 and \frac{1}{20} to get \frac{7}{20}.

$$\frac{7}{20}+8\times \frac{1}{4}+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Multiply 8 and \frac{1}{4} to get \frac{8}{4}.

$$\frac{7}{20}+\frac{8}{4}+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Divide 8 by 4 to get 2.

$$\frac{7}{20}+2+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Convert 2 to fraction \frac{40}{20}.

$$\frac{7}{20}+\frac{40}{20}+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Since \frac{7}{20} and \frac{40}{20} have the same denominator, add them by adding their numerators.

$$\frac{7+40}{20}+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Add 7 and 40 to get 47.

$$\frac{47}{20}+9\times \frac{2}{5}+10\times \frac{3}{10}$$

Express 9\times \frac{2}{5} as a single fraction.

$$\frac{47}{20}+\frac{9\times 2}{5}+10\times \frac{3}{10}$$

Multiply 9 and 2 to get 18.

$$\frac{47}{20}+\frac{18}{5}+10\times \frac{3}{10}$$

Least common multiple of 20 and 5 is 20. Convert \frac{47}{20} and \frac{18}{5} to fractions with denominator 20.

$$\frac{47}{20}+\frac{72}{20}+10\times \frac{3}{10}$$

Since \frac{47}{20} and \frac{72}{20} have the same denominator, add them by adding their numerators.

$$\frac{47+72}{20}+10\times \frac{3}{10}$$

Add 47 and 72 to get 119.

$$\frac{119}{20}+10\times \frac{3}{10}$$

Cancel out 10 and 10.

$$\frac{119}{20}+3$$

Convert 3 to fraction \frac{60}{20}.

$$\frac{119}{20}+\frac{60}{20}$$

Since \frac{119}{20} and \frac{60}{20} have the same denominator, add them by adding their numerators.

$$\frac{119+60}{20}$$

Add 119 and 60 to get 179.

$$\frac{179}{20}$$

Factor

$$\frac{179}{2 ^ {2} \cdot 5} = 8\frac{19}{20} = 8.95$$