Solve 3a-4=a+b

$$3 a - 4 = a + b$$

Solve for a

$$a=\frac{b+4}{2}$$

Steps for Solving Linear Equation

Subtract a from both sides.

$$3a-4-a=b$$

Combine 3a and -a to get 2a.

$$2a-4=b$$

Add 4 to both sides.

$$2a=b+4$$

Divide both sides by 2.

$$\frac{2a}{2}=\frac{b+4}{2}$$

Dividing by 2 undoes the multiplication by 2.

$$a=\frac{b+4}{2}$$

Divide b+4 by 2.

$$a=\frac{b}{2}+2$$

Solve for b

$$b=2\left(a-2\right)$$

Solution Steps

Swap sides so that all variable terms are on the left hand side.

$$a+b=3a-4$$

Subtract a from both sides.

$$b=3a-4-a$$

Combine 3a and -a to get 2a.

$$b=2a-4$$