Answer:
15. x = 4
16. a = 19
Step-by-step explanation:
"Cross multiply" essentially means "multiply both sides of the equation by the product of the denominators."
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<h3>15.</h3>
This is an example of a problem in which cross-multiplying introduces the need for an extra step: divide by 3. Had we simply multiplied by the denominator of the x-term, we would have been finished in one step:
x = 6(2/3) = 4
That is, rather than multiplying by the <em>product of the denominators</em>, sometimes the problem can be solved more easily if you multiply by their <em>least common multiple</em>.
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<h3>16.</h3>
