## Substitution Exercise

1. If p = 2, q = 3 and r = 4 find the values of the following terms by substituting:

 a 2p b 4r c 3q d pq e qr f pr g p2 h 3pq i 4pr j 5pqr k qr2 l p2q2r2

2. Substitute the values given in the following formulae to find the value of the unknown variable. Make sure that the correct units are given.

 (a) V = d/t find the velocity v, when d = 80 km and t = 4 hours (b) A = l w find the area A of a rectangle , when l = 20 cm and w = 5 cm (c) C = 2πr find the circumference C, when π = 3 and r = 8 cm (d) V = 1/3Ah find the volume V, when A = 21 cm2 and h = 6 cm

3. A group of 17 adults and children go to watch a soccer game.

 There are 10 adults and 7 children. The admission charges are: Adults \$5Children \$2 The formula for the cost of admission is C = 5a + 2b. Where a is the number of adults and b is the number of children.

Use the formula to find the cost for the group.

4. Complete the table, by substituting the values down the side into the terms along the top.

 x 2x x + 2 x2 2 + 3x 1 2 5 8