Solve 30=r*20+(1-r)*60

$$30 = r \times 20 + ( 1 - r ) \times 60$$

Solve for r

$$r=\frac{3}{4}=0.75$$

Steps for Solving Linear Equation

Use the distributive property to multiply 1-r by 60.

$$30=r\times 20+60-60r$$

Combine r\times 20 and -60r to get -40r.

$$30=-40r+60$$

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

$$-40r+60=30$$

Subtract 60 from both sides.

$$-40r=30-60$$

Subtract 60 from 30 to get -30.

$$-40r=-30$$

Divide both sides by -40.

$$r=\frac{-30}{-40}$$

Reduce the fraction \frac{-30}{-40} to lowest terms by extracting and canceling out -10.

$$r=\frac{3}{4}$$