When we have a proportion a/b = c/d, we can rewrite it as ad = bc. we _ _ it. (2 words)

'We cross multiplied it'.

Step-by-step explanation:

Lets first understand our proportion and re write in correct Fraction form as:

    Eqn(1).

where:

and are the Numerators

and are the Denominators

Now the question sais that Eqn(1). can be written as

This is true since here:

'We cross multiplied it'.

Cross Multiplication is used when we have equations of the form Eqn(1) where there is one fraction on the left hand side and one fraction on the right hand side, so that the Numerator of the left hand side is multiplied with the Denominator of the right hand side and similarly the Denominator of the left hand side is multiplied with the Numerator of the right hand side (like a diagonal multiplication).  

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

i think the answer is true

step-by-step explanation: