Solve 7x+3y=8 and 4x-y=-9 simultaneously

Answer: x = - 1 and y = 5

Step-by-step explanation:

7x + 3y = 8 ... equation 1

4x - y = - 9 ... equation 2

Solving the simultaneous linear equation by substitution method, make y the subject of the formula from equation 2, we have

y = 4x + 9 ... equation 3

substitute y = 4x + 9 into equation 1, we have;

7x + 3 (4x + 9) = 8

7x + 12x + 27 = 8

19x + 27 = 8

subtract 27 from both sides

19x = - 19

divide through by 19

x = - 1

substitute x = - 1 into equation 3, we have

y = 4 (-1) + 9

y = - 4 + 9

y = 5

Therefore:

x = - 1 and y = 5