If 2a-3b11 and ab7 find the value of a and b?

Answer 1

I take it you mean if 2a - 3b = 11 an a+b = 7 then find the value of a and b.

The problem with this site is that the questions can't contain things like the equal sign

To solve a problem like this we need to get two of the letter values to be the same, and then we can subtract one equation from the other.

so, if we multiply the second equation by -2 we get

-2a - 2b = -14

No to that we add

2a - 3b = 11

and we get

-5b = -3

so b = 3/5

Now we can replace the b in the second equation and we get

a + 3/5 = 7

So we can see that a must equal 62/5

and if we put these values into the first equation the two sides of the equation should balance...

2 (62/5) - 3(3/5) should equal 11... so we'll multiply the values and check

2 (62/5) = 124/5

and

3(3/5) = 9/5 = 14/5

and indeed 124/5 - 14/5 does indeed = 11.