Brackets, fractions and deeper modelling

Answer: −1

1. Add 10 and divide by 5:x+7=6.
2. Subtract 7:x=−1.
3. Substitution gives 20 on both sides.

Answer: 38

1. Let x be the distance in kilometres.
2. 5.00+1.25x=33.50+0.50x.
3. Subtract the lower rate and the first fee: 0.75x=28.50.
4. So x=38km;
5. both fares are $52.50.

Answer: 16

1. Expand and collect: 2x=32.
2. Divide by 2:x=16.
3. Both sides equal 189 after substitution.