Occasionally, if you want to use equation combination to get rid of a variable, you’ll have to multiply each equation by a different number.
For example, in the following question, a good strategy for getting rid of y is to multiply
the first equation by –5 and the second equation by what number?
In the space provided, type the number you would multiply the second
equation by to make y cancel out, then click Continue.
Answer: 2
If you choose –5 for the first equation, you’ll want to select 2 for the second equation to make the y-variable disappear:
Added together, y will drop out, and you’ll be able to solve for x.
Now let’s move on to our second method…substitution.
|