Solve (400-300)a+(350-255)(30-a)=3000

$$( 400 - 300 ) a + ( 350 - 255 ) ( 30 - a ) = 3000$$

Solve for a

$$a=30$$

Steps for Solving Linear Equation

Subtract 300 from 400 to get 100.

$$100a+\left(350-255\right)\left(30-a\right)=3000$$

Subtract 255 from 350 to get 95.

$$100a+95\left(30-a\right)=3000$$

Use the distributive property to multiply 95 by 30-a.

$$100a+2850-95a=3000$$

Combine 100a and -95a to get 5a.

$$5a+2850=3000$$

Subtract 2850 from both sides.

$$5a=3000-2850$$

Subtract 2850 from 3000 to get 150.

$$5a=150$$

Divide both sides by 5.

$$a=\frac{150}{5}$$

Divide 150 by 5 to get 30.

$$a=30$$