Question

Determine the value of a + b in the system of equations below.

5a + 4b = 22
7a-b= 11

Answer 1

We have a + b as;

2 + 3 = 5

Explanation:

Here, we want go get the value of a and b

from the second equation, we can get an expression for b

We have this as;

7a - b = 11

Thus,

b = 7a - 11

Now, from here, we can substitute the value of b into the first equation

We have this as;

5a + 4(7a - 11) = 22

5a + 28a -44 = 22

33a = 22 + 44

33a = 66

a = 66/33

a = 2

Recall;

b = 7a - 11

substituting the value of a from above;

b = 7(2) - 11

b = 14 - 11

b = 3