Ashli-Ann D. answered • 04/05/13

Yes you can! Better English and Homework can be attained!

The correct answer is (a). The solution is a=-5 and b=3. This is (-5,3) written as an ordered pair.

a+6b=13

a+4b=7

We want to get rid of one variable (a or b) and so we need to either add or subtract one equation from the other.

1) Subtract equation 2 (the bottom one) from equation 1.

a+6b=13

- a+4b=7

2b=6

The variable a is eliminated as a minus a leaves nothing. As seen above only one variable (b) remains.

2) Solve new equation to find b.

2b=6

b=6/2

b=3

3) Replace b with 3 in either equations to find the value of a.

a+6b=13

a+6(3)=13

a+18=13

a=13-18

a=-5

Therefore there is one solution : a=-5 and b=3. This can be written as (-5,3).

You can plug these values into the other equation to check if they are correct.