Question

15 a2 − 1 = 5 2a − 2 Which equation results from cross-multiplying?

a.) 15(a2 – 1) = 5(2a – 2)

b.) 15(2a – 2) = 5(a2 – 1)

c.) 15(a 2 

– 1)(2 a  – 2) = 5(2 a  – 2)( a 2  – 1)

Answer 1

Option (b) is correct.

`{15}(2a-2)={5}(a^2-1)` equation results from cross-multiplying.

Explanation:

Given : expression
`(15)/(a^2-1)=(5)/(2a-2)`

We have to find the results obtained from cross-multiplying the given expression and choose the correct option from given options.

Consider the given expression
`(15)/(a^2-1)=(5)/(2a-2)`

Cross multiply is done by Multiplying the top and bottom of the first fraction by the bottom number of the second fraction.

Thus, for the given expression
`(15)/(a^2-1)=(5)/(2a-2)`

We have,

`{15}(2a-2)={5}(a^2-1)`

Thus, option (b) is correct.

Answer 2

Given the expression:
15/(a²-1)=5/(2a-2)
cross-multiplying the above we get:
15×(2a-2)=5×(a²-1)
this will give us:
15(2a-2)=5(a²-1)

Answer: b]15(2a – 2) = 5(a2 – 1)