Q4Multiple choice
The number of teeth and the age of a person vary
- (a)directly with each other.
- (b)inversely with each other.
- (c)neither directly nor inversely with each other.
- (d)sometimes directly and sometimes inversely with each other. Direct Variation: If the relationship of variables y and x can be expressed in the form: y = kx for some constant k, then we say that y varies directly with x or that y is directly proportional to x. The number k is called the constant of proportionality for the relationship. The close connection between multiplication and division of numbers implies that if y is directly proportional to x, then = k . The symbolic form = k shows that the ratio of y to x is constant, for any corresponding values of y and x.
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(a) directly with each other.