The cost of the tennis ball is $0.05.
Let the cost of tennis racket be R.
Let the cost of tennis ball be B.
To find the cost of the tennis ball:Translating the word problem into an algebraic expression, we have;
R+B=2.10 ....equation 1
R=B+2 .....equation 2
Substituting eqn 2 into eqn 1, we have;
B+2+B=2.10
2B+2=2.10
2B=2.10−2
2B=0.10
B= 0.10/2
Tennis ball, B = $0.05
Therefore, the tennis ball cost $0.05.
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