Solve 20left(80-xright)+30left(80-xright)/80=0

$$\frac{ 20 \left( 80-x \right) +30 \left( 80-x \right) }{ 80 } =0$$

Solve for x

$$x=80$$

Steps for Solving Linear Equation

Multiply both sides by 80. Anything times zero gives zero.

$$20\left(80-x\right)+30\left(80-x\right)=0$$

Use the distributive property to multiply 20 by 80-x.

$$1600-20x+30\left(80-x\right)=0$$

Use the distributive property to multiply 30 by 80-x.

$$1600-20x+2400-30x=0$$

Add 1600 and 2400 to get 4000.

$$4000-20x-30x=0$$

Combine -20x and -30x to get -50x.

$$4000-50x=0$$

Subtract 4000 from both sides. Anything subtracted from zero gives its negation.

$$-50x=-4000$$

Divide both sides by -50.

$$x=\frac{-4000}{-50}$$

Divide -4000 by -50 to get 80.

$$x=80$$