Question

How do I find these answers I aways get confused..

How do I know if is is a solution
There are infinitely many solutions
There is no solution

Answer 1

an example would be 8a+9b=3 && 8a+b=27
Idk what I would ddo

Answer 2

Isolate one variable then plug it into other sides and solve.

Let me show you how to solve it.
Let isolate b in second equation because it's easy.

8a + b = 27

b = 27 - 8a

now plug it into other equation.

8a + 9b = 3
8a + 9(27 - 8a) = 3

Now solve for a.

8a + 9(27) - 9(8a) = 3
8a + 243 - 72a = 3

Subtract both sides by 243:

8a - 72a = 3 - 243
8a - 72a = -240

Combine the like terms.

(8 - 72)a = -240

-64a = -240

Divide both siddes by -64.

a = -240/-64
a = 240/64
a = 15/4

Now plug the value of a into other equation and find b.

8a + b=27
8(15/4) + b=27

30 + b = 27

Subtract both sides by 30:

b = 27 - 30
b = -3

So a = 15/4 and b = -3

Hope this helps.

Answer 3

so what would the ordered pay be???? (15,4)

Answer 4

This is called checking the consistency of linear equations, you will get this by practice when you solve many equations for now for identification: if two equations are given : a1x+b1y+c=0 & a2x+b2y+c=0 then if \[a1/a2 \neq b1/b2\] then one unique solution, if \[a1/a2=b1/b2=c1/c2 \] then infinite solution and if
\[a1/a2=b1/b2 \neq c1/c2\] then it is no solution. I hope this will help....moreover you can refer this: http://ncert.nic.in/ncerts/textbook/textbook.htm?jemh1=3-14 or just go to the site: http://ncert.nic.in/ncerts/textbook/textbook.htm on the upper tab put class X, Subject Mathematics and book title Mathematics.....Open Chapter 3,read through you will be able to grasp.

Answer 5

@Talyababyyy hope you got it......check on the site you will understand it really well..... http://ncert.nic.in/ncerts/textbook/textbook.htm?jemh1=3-14