Simultaneous equations

Just having problems with this problem:

2a + ab = -1
a - 3b = 2

At the moment I'm just staring at it without a clue, although I'm guessing a third equation needs to be introduced. If someone could point me in the correct direction I'd be really grateful.

Thanks in advance.

Reply 1

davros

16

Original post by coatsoft

Just having problems with this problem:

2a + ab = -1
a - 3b = 2

At the moment I'm just staring at it without a clue, although I'm guessing a third equation needs to be introduced. If someone could point me in the correct direction I'd be really grateful.

Thanks in advance.

Use the 2nd eq to write a in terms of b, then substitute into the 1st eq so you have a quadratic eq in b to solve.

Reply 2

coatsoft

OP

16

Original post by davros

Use the 2nd eq to write a in terms of b, then substitute into the 1st eq so you have a quadratic eq in b to solve.

How I didn't spot that I don't know :mad:

. Thanks

.

Reply 3

SlowlorisIncognito

16

Hi

I've moved this thread to the maths study help forum, as the university subject forums are for discussion about university courses/applying for those courses rather than help with specific problems.

Reply 4

coatsoft

OP

16

Original post by SlowlorisIncognito

Hi

I've moved this thread to the maths study help forum, as the university subject forums are for discussion about university courses/applying for those courses rather than help with specific problems.