Linear equations are equations of a straight line.
The other equation could be [tex]\mathbf{a + 3b = 8}[/tex]
The equation is give as:
[tex]\mathbf{a + b = 4}[/tex]
The solution is given as:
[tex]\mathbf{(a,b) = (2,2)}[/tex]
From the list of given options, the other equation is:
[tex]\mathbf{a + 3b = 8}[/tex]
Substitute [tex]\mathbf{(a,b) = (2,2)}[/tex] for proof
[tex]\mathbf{2 + 3 \times 2= 8}[/tex]
[tex]\mathbf{2 + 6= 8}[/tex]
[tex]\mathbf{8= 8}[/tex]
The above equation is true.
Hence, the other equation could be [tex]\mathbf{a + 3b = 8}[/tex]
Read more about system of linear equations at:
https://brainly.com/question/20379472
