Solve 79*0.2+65*0.2+70*0.3+x*0.3=77

$$79 \cdot 0.2+65 \cdot 0.2+70 \cdot 0.3+x \times 0.3=77$$

Solve for x

$$x = \frac{272}{3} = 90\frac{2}{3} \approx 90.666666667$$

Steps for Solving Linear Equation

Multiply 79 and 0.2 to get 15.8.

$$15.8+65\times 0.2+70\times 0.3+x\times 0.3=77$$

Multiply 65 and 0.2 to get 13.

$$15.8+13+70\times 0.3+x\times 0.3=77$$

Add 15.8 and 13 to get 28.8.

$$28.8+70\times 0.3+x\times 0.3=77$$

Multiply 70 and 0.3 to get 21.

$$28.8+21+x\times 0.3=77$$

Add 28.8 and 21 to get 49.8.

$$49.8+x\times 0.3=77$$

Subtract 49.8 from both sides.

$$x\times 0.3=77-49.8$$

Subtract 49.8 from 77 to get 27.2.

$$x\times 0.3=27.2$$

Divide both sides by 0.3.

$$x=\frac{27.2}{0.3}$$

Expand \frac{27.2}{0.3} by multiplying both numerator and the denominator by 10.

$$x=\frac{272}{3}$$