5 Footballs and 3 tennis balls cost £2.30, 4 Footballs and 2 tennis balls cost £1.80. What is the total cost of 1 football and 1 tennis ball?

(simple algebraic substitution equations)
assign each an algebraic term to form equations > footballs = f, tennis balls = tequation 1 > 5f + 3t = £2.30equation 2 > 4f + 2t = £1.80
(you could multiply equations 1 & 2 appropriately to get a common term and then cancel, then substitute to find other term, but faster grade 7-9 method here is to simply notice that equation 1 minus equation 2 gives you the equation the question asks for)
equation 1 - equation 2 = f + t = £0.50therefore, a tennis ball and a football cost 50 pence