Question #15aab
1 Answer
Explanation:
The question to be solved is.
5p-7q=-13to(1)5p−7q=−13→(1)
2p+7q=34to(2)2p+7q=34→(2) The aim here is to eliminate one of the variables from the equations by performing operations on them. We then have a one variable equation which we can solve. Then substitute this value into either one of the 2 given equations and solve for the other variable.
I have labelled the equations to assist.
Note that in (1) there is a - 7q and in (2) there is + 7q
Adding these together will eliminate the variable q, which is what we want.
Add (1) and (2) together term by term on both sides.
rArr7p+0=21rArr7p=21rArrp=3⇒7p+0=21⇒7p=21⇒p=3
Now substitute p = 3 into (1) or (2). I'll choose (2) you can perhaps try (1).
rArr(2xx3)+7q=34⇒(2×3)+7q=34
rArr6+7q=34rArr7q=28rArrq=4⇒6+7q=34⇒7q=28⇒q=4 Hope this helps.
